The correct answer is C. The developer did not update the Docker image tag to a new version.

C. The developer did not update the Docker image tag to a new version. This is correct. When deploying an application to Amazon EKS, the developer needs to specify the Docker image tag that contains the application code and configuration. If the developer does not update the Docker image tag to a new version after making changes to the application, the EKS cluster will continue to use the old Docker image tag that references the original backend resources. To fix this issue, the developer should update the Docker image tag to a new version and redeploy the application to the EKS cluster.

A. The developer did not successfully create the new AWS account. This is incorrect. The creation of a new AWS account is not related to the application’s connection to the backend resources. The developer can use any AWS account to host the EKS cluster and the backend resources, as long as they have the proper permissions and configurations.

B. The developer added a new tag to the Docker image. This is incorrect. Adding a new tag to the Docker image is not enough to deploy the changes to the application. The developer also needs to update the Docker image tag in the EKS cluster configuration, so that the EKS cluster can pull and run the new Docker image.

D. The developer pushed the changes to a new Docker image tag. This is incorrect. Pushing the changes to a new Docker image tag is not enough to deploy the changes to the application. The developer also needs to update the Docker image tag in the EKS cluster configuration, so that the EKS cluster can pull and run the new Docker image.

The solution that will meet the requirements is to add a second cache behavior to the distribution with the same origin as the default cache behavior. Set the path pattern for the second cache behavior to the path of the login page, and make viewer access unrestricted. Keep the default cache behavior’s settings unchanged. This way, the login page can be accessed without authentication, while all other content remains secure and requires signed cookies. The other options either do not allow unauthenticated access to the login page, or expose private content to unauthorized users.

S3Bucket and S3Key: These properties in a CloudFormation AWS::Lambda::Function resource specify the location of the function ' s code in S3.

Least Development Effort: This solution minimizes code changes, relying on CloudFormation to reference the existing S3 deployment package.

Amazon S3 is a service that provides highly scalable, durable, and secure object storage. Amazon DynamoDB is a fully managed NoSQL database service that provides fast and consistent performance with seamless scalability. AWS Lambda is a service that lets developers run code without provisioning or managing servers. The developer can configure an S3 event to invoke a Lambda function that inserts records into DynamoDB whenever a new file is added to the S3 bucket. This solution will meet the requirement of inserting a record into DynamoDB as soon as a new file is added to S3.

HTTP Status Codes: Each HTTP status code has a specific meaning in RESTful APIs.

HTTP 405 (Method Not Allowed): Indicates that the request method (e.g., POST) is not supported for the specified resource.

HTTP 401 (Unauthorized): Represents a failure to authenticate, which is the appropriate response for invalid login credentials.

The access restriction must be applied to the REST API, not merely to the static website bucket. API Gateway resource policies can control who can invoke an API and can restrict access by source IP address ranges or CIDR blocks. That directly satisfies the requirement that only computers from the corporate CIDR range can invoke the API. An S3 bucket policy would restrict access to the static website content, but the API endpoint could still be called directly unless API Gateway is also protected. An IAM service- linked role is not the correct control plane for client source IP filtering. Network ACLs apply at the subnet level inside a VPC and do not control public API Gateway invocation. AWS documentation confirms API Gateway resource policies support specified source IP address ranges. ( AWS Documentation )

===============

To rotate database credentials without downtime, Secrets Manager recommends the alternating users (dual user) rotation strategy. With a single-user strategy, Secrets Manager changes the password for the same database user that the application is actively using. If the application continues using cached/old credentials during rotation, authentication failures and downtime can occur.

With the alternating users strategy, two database users exist (often named something like appuser and appuser_clone). Secrets Manager alternates which user is “active” in the secret. During rotation, Secrets Manager updates the inactive user’s password, verifies it, updates the secret to point to the newly updated user, and then (optionally) retires the old credentials. This approach minimizes disruption because there is always one known-good credential set while the other is being updated.

The question specifically requires regular rotation using Secrets Manager. That is achieved by enabling automatic rotation on the secret with a schedule (for example, every 30/60/90 days). Automatic rotation invokes the rotation Lambda (AWS-provided or configured) and performs the workflow without manual intervention.

Option D combines both requirements: automatic rotation plus the alternating users strategy for high availability and no downtime.

Option B mentions alternating users but “managed rotation” is not the standard term used in these choices as the primary differentiator—automatic rotation is the necessary capability to rotate regularly without manual effort.

Options A and C (single user) are more likely to cause downtime during rotation.

Therefore, configure automatic rotation with the alternating users rotation strategy.

Why Option A is Correct:DynamoDB supports incremental exports to Amazon S3 natively, making data analytics-ready with minimal operational overhead.

Why Other Options are Incorrect:

Option B: DynamoDB Streams require additional processing logic to write to S3, increasing complexity.

Option C & D: Using EMR for data movement adds unnecessary operational overhead compared to native exports.

AWS Documentation References:

DynamoDB Exports to S3

The requirement has two parts: (1) authenticate users with a third-party SAML IdP , and (2) after authentication, allow those users to access AWS services like Amazon S3 and DynamoDB. The AWS pattern for this is to federate the external identity into AWS and then exchange that identity for temporary AWS credentials .

Amazon Cognito identity pools are designed to provide AWS credentials to authenticated users (via AWS STS) so the users can call AWS services directly or through an application backend. Identity pools support federation with external identity providers, including SAML 2.0 . When a user authenticates with the third-party SAML IdP, the identity pool can accept the SAML assertion, map the user to an IAM role, and return temporary, scoped credentials (AccessKeyId/SecretAccessKey/SessionToken) associated with that role. Those credentials can be restricted using IAM policies to only the required S3 buckets, DynamoDB tables, and actions, satisfying least privilege.

Option A is incorrect because a Cognito user pool is primarily a user directory and OIDC/OAuth provider for application authentication; while user pools can integrate with SAML IdPs for federation, user pools alone do not directly issue AWS service credentials. The key requirement here is access to S3/DynamoDB, which is the role of an identity pool . Option C is not appropriate because IAM is not intended to provide end-user sign-up/sign-in for external users; it is for AWS identities and permissions. Option D is unrelated: CloudFront signed URLs control access to CloudFront-distributed content and do not authenticate users with SAML or provide AWS credentials.

Therefore, B meets both requirements: federate SAML authentication through a Cognito identity pool and provide temporary AWS credentials for accessing S3 and DynamoDB.