While examining the output of a show run command on the Cisco MDS 9000 Series, you notice that the statement interface GigabitEthernet2/1.2 appears in the output. What does this mean?

A.
It refers to the second FCIP tunnel that is configured on port GigabitEthernet2/1.

B.
It refers to a VLAN subinterface on port GigabitEthernet2/1.

C.
It means that port GigabitEthernet2/1 is assigned to VSAN 2.

D.
It is a mistake in the interface configuration.