The error in the exhibit occurs because an access interface can only be a member of one VLAN, but it is currently configured with the "default" VLAN and is trying to be added to VLAN "v11." To resolve the issue, the correct command is:
delete ge-0/0/2 unit 0 family ethernet-switching vlan members default
This command removes the interface from the "default" VLAN, allowing it to be part of VLAN
"v11" as intended.

The exhibit shows the output of the command show vlans brief, which displays brief information about VLANs and their associated interfaces.
The output has four columns: Routing instance, VLAN name, Interfaces, and Tagging. The * symbol indicates that the interface is active, meaning that it is up and forwarding traffic. This can be verified by the command show interfaces terse, which displays the status of the interfaces.

In Rapid Spanning Tree Protocol (RSTP), there are several port roles that determine the behavior of the port in the spanning tree 1 2 3 . The roles include root, designated, alternate, backup, and disabled 1 2 3 .
The discarding state is associated with the backup, alternate, and disabled roles 1 2 3 . In a stable topology with consistent port roles throughout the network, RSTP ensures that every root port and designated port immediately transition to the forwarding state while all alternate and backup ports are always in the discarding state 2 . Disabled ports are also in the discarding state 3 .
Therefore, options B, C, and D are correct.