Responsive layouts use CSS media queries to apply different style rules according to the viewport width or device characteristics. In this scenario, the three wireframes represent desktop, tablet, and mobile breakpoints. The desktop layout should use @media only screen and (min-width: 1025px) because desktop screens are the widest target group and begin above the tablet maximum width. The tablet layout should use @media only screen and (min-width: 481px) and (max-width: 1024px) because it covers the middle range between mobile and desktop. The mobile layout should use @media only screen and (min-width: 285px) and (max-width: 480px) because it targets the smallest viewport range shown in the available choices. The option @media only screen and (max-width: 1025px) and (min-width: 1920px) is logically invalid because a viewport cannot simultaneously be at least 1920 pixels wide and no more than 1025 pixels wide. References/topics: responsive web design, CSS media queries, viewport breakpoints, mobile layout, tablet layout, desktop layout.

The correct methods are setItem(), removeItem(), and clear(). The HTML5 Web Storage API exposes localStorage as a persistent key-value storage object for the current origin. Data stored in localStorage remains available after page reloads and browser restarts unless it is explicitly removed or cleared. setItem(key, value) stores a value under a named key or updates the value if the key already exists. removeItem(key) deletes one specific key-value pair from storage. clear() removes all key-value pairs from the storage object for that origin. These methods are part of the standard Storage interface used by both localStorage and sessionStorage. write is not a Web Storage method; it is associated with document-writing behavior, not application state storage. cookie is also incorrect because cookies are a separate browser storage mechanism accessed through document.cookie, not a method of localStorage. References/topics: Web Storage API, localStorage, Storage interface, application state, persistent key-value data.

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First drop-down: datalist

Second drop-down: vehicles

Third drop-down: < /datalist >

The correct element is < datalist > because the interface requires a text input that provides selectable suggestions while still allowing the user to type. The < input > element uses list= " vehicles " , so it must be connected to a < datalist > element whose id is exactly vehicles. The id cannot be vehicle, because vehicle is already the input element’s own identifier and does not match the value used by the list attribute. The < option > elements inside the datalist define the suggested values: Motorcycle, Truck, Boat, Car, and Bicycle. ul, ol, and li are list-markup elements and do not create input suggestions. select would create a fixed dropdown list, but it would not match the editable input-with-suggestions behavior shown. The closing tag must match the opening datalist element, so the final selection is < /datalist > .

The correct answer is D because an SVG ellipse is created with the < ellipse > element and the required geometry attributes cx, cy, rx, and ry. The cx attribute defines the x-coordinate of the ellipse’s center point, and cy defines the y-coordinate of the center point. The rx attribute defines the horizontal radius, while ry defines the vertical radius. In option D, cx= " 200 " and cy= " 80 " correctly position the center of the ellipse, while rx= " 100 " and ry= " 50 " correctly define an ellipse that is wider than it is tall. Option A is invalid because the element name is misspelled as < ellipsp > , so the browser will not interpret it as an SVG ellipse. Option B incorrectly uses x and y attributes instead of the ellipse-specific center and radius attributes. Option C correctly uses cx and cy, but incorrectly uses x and y where rx and ry are required. References/topics: SVG markup, < svg > container, < ellipse > element, center coordinates, horizontal radius, vertical radius.

First blank: img

Second blank: filter:

Third blank: grayscale(100%)

Fourth blank: blur(8px)

The correct CSS selector is img because the requirement applies the visual effect to gallery images. The correct property is filter:, not transform:, because CSS filters modify the rendered appearance of an element using image-processing effects such as blur, grayscale, opacity, brightness, contrast, and shadows. The filtered sample appears blurred and colorless, so the appropriate filter functions are grayscale(100%) and blur(8px). grayscale(100%) removes all color from the image, converting it to a black-and-white rendering. blur(8px) obscures visual details, making the image difficult to recognize until the protected or authorized state changes the styling. The filter keyword without a colon is not a valid CSS declaration in this context. brightness(40%) and opacity(50%) could further obscure an image, but they are not required to reproduce the shown filtered result. The final declaration is therefore filter: grayscale(100%) blur(8px);.

The correct coordinate is 50,50. In an HTML5 canvas, the coordinate system begins at the upper-left corner of the canvas. The x-coordinate increases as you move to the right, and the y-coordinate increases as you move downward. Therefore, 0,0 represents the top-left corner of the entire white canvas area. In the displayed image, the filled black square is not positioned at the top-left edge, top-center, or left-center of the canvas. Instead, its upper-left corner is offset both horizontally and vertically from the origin. Among the available choices, 50,50 is the only coordinate that moves the square 50 units to the right and 50 units down from the canvas origin. This matches the visual placement of the filled square inside the white canvas. Option A would place the square at the canvas origin. Option B would place it along the left side, halfway down. Option C would place it along the top edge, halfway across. References/topics: HTML5 canvas coordinate system, x/y positioning, drawing rectangles, fillRect(x, y, width, height).

The valid selections are mouseup, scroll, and blur. A < canvas > element is represented by HTMLCanvasElement, which inherits from HTMLElement; therefore, it participates in the normal DOM event model for element-based interaction. mouseup is valid because it is fired on an Element when a pointing-device button is released while the pointer is over that element, which is a common canvas interaction pattern for drawing tools, games, drag tracking, and selection behavior. scroll is valid as an element event when an element is scrolled, and the HTML event-handler index lists onscroll for HTML elements. blur is also valid because it fires when an element loses focus; a canvas can participate in focus workflows, particularly when made focusable with attributes such as tabindex. play is excluded in this certification context because it is a media playback event associated with HTMLMediaElement behavior, not canvas graphics interaction. datareceived is not a standard HTML canvas or DOM event. References/topics: canvas DOM interaction, element event listeners, mouse events, focus events, scroll events.

The value stored in num is the number of key-value pairs currently stored in localStorage. The localStorage object implements the Web Storage Storage interface, which stores data as named string key/value entries for the current origin. Its length property is read-only and returns the number of data items stored in that Storage object, not the size of the stored data and not the remaining capacity. MDN’s Storage reference explicitly defines length as returning the number of data items stored, and its example shows that after three items are added to localStorage, localStorage.length returns 3. Therefore, if the storage area contains five named entries, num receives 5; if it contains no entries, num receives 0. Option A is incorrect because available bytes are not exposed through length. Option B is unrelated to Web Storage. Option C is incorrect because browser storage quota or capacity is separate from the length property. References/topics: Web Storage API, localStorage, Storage.length, key-value storage, application state.

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The correct answer is A because the code at line 03 creates an object by calling a constructor function with the new keyword. A constructor function must be declared with the same identifier used in the new Student( " David " , " Hamilton " ) expression. Inside the constructor, instance members should be assigned through this, because this refers to the newly created object. Option A correctly initializes this.firstname, this.lastname, and this.fullname, so beststudent.fullname is available at line 04 and evaluates to " David Hamilton " . Option B is invalid JavaScript syntax because var student(firstName, lastName) is not a valid function declaration. Option C is also invalid syntax for the same reason: var Student(firstname, lastname) cannot declare a constructor. Option D uses a valid function declaration, but it assigns firstname, lastname, and fullname without this, which creates or references non-encapsulated variables rather than properties of the constructed object. References/topics: JavaScript constructor functions, new keyword, object instance properties, this, custom classes.

Media queries support responsive web design and allow different CSS rules to be applied at different screen sizes, device characteristics, or breakpoints. MDN describes media queries as a CSS mechanism for applying styles depending on media type and device or viewport characteristics, including width, height, resolution, and orientation. This is the foundation of responsive design because a page can adapt its layout for phones, tablets, laptops, and desktop displays without changing the HTML document. Breakpoints are the points where the design changes; MDN identifies them as the points where a media query is introduced to improve layout behavior across viewport sizes. Statement A is not generally correct because media queries are primarily a styling and layout mechanism, not a direct performance optimization. They can sometimes help avoid unsuitable layouts, but performance improvement is not their defining purpose. Statement D is incorrect because media queries are CSS rules; they do not execute or dynamically process JavaScript code. References/topics: responsive design, CSS media queries, viewport width, breakpoints, adaptive layout rules.

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