Refer to the exhibit.

The selected resolution is Assign a new domain ID to the isolated switch because the failure is in the Fibre Channel/FCoE control path around MDS, VSAN. Cisco MDS and Nexus platforms separate configuration from operational state: a VSAN, zone, vFC binding, device alias, or port-security entry can exist in configuration but still fail if it is not active, correctly merged, or allowed on the link. The correct option addresses the fabric condition that prevents communication. The incorrect options are technically adjacent but would not repair the specific dependency; for example, changing unrelated databases or resetting ports without correcting policy leaves the same failure to recur. Cisco SAN troubleshooting therefore starts with port role and VSAN checks, then confirms fabric services such as fcdomain, FSPF, zoning, fabric binding, and name-server information. The expected validation is that the port becomes operational, the initiator and target appear in the appropriate databases, and permitted zone members can communicate.