The correct answer to your question is  C. Option C . Here is why:

Option C shows the configuration of the  chassis  statement, which defines the properties of the router chassis, such as the number of aggregated Ethernet interfaces, the number of FPCs, and the number of PICs 1 .

To enable aggregated Ethernet interfaces on a router, you need to specify the  aggregated-devices  statement under the  chassis  statement and set the  ethernet  parameter to the desired number of interfaces 2 . For example, to enable two aggregated Ethernet interfaces, you can use the following configuration:

chassis { aggregated-devices { ethernet { device-count 2; } } }

Option C shows this configuration with the device-count set to 2, which will enable two aggregated Ethernet interfaces on the router. The other options do not show this configuration and will not enable any aggregated Ethernet interfaces on the router.

Therefore, option C is the correct answer to your question.

According to the Juniper documentation 1 , MAC limiting is a feature that enhances port security by limiting the number of MAC addresses that can be learned within a VLAN. When the MAC limit is exceeded, the switch can perform different actions, such as ignoring, dropping, logging, shutting down, or disabling the offending port.  The default action is to drop the packets with new MAC addresses and log a message 2 . Therefore, the correct answer is B.

The other options are not correct because:

A. The switch will not shut down the offending port for five minutes by default.  This is a configurable action, but not the default one 2 .

C. The switch will not flood traffic out of all ports for the offending MAC address by default.  This is a possible consequence of ignoring the packets with new MAC addresses, but not the default action 2 .

D. The switch will not shut down MAC learning on the offending port for five minutes by default.  This is another configurable action, but not the default one 2 .