You have created a new IS-IS adjacency between identical routers over two STM-4 circuits. After
enabling no-keepalives on the interfaces, they come up and you are able to ping between the
routers. However, the IS-IS adjacency still will not establish.
Which step will determine the cause of the problem?

A.
Disable no-keepalives from the interfaces and issue a show isis adjacency command.

B.
Enable family iso on all the SONET interfaces, commit, and test the circuits.

C.
Disable cisco-hdlc encapsulation, enable ppp encapsulation, commit, and test the circuits.

D.
Disable no-keepalives from the interfaces and issue a show interfaces extensive command for
each of the SONET interfaces.

Explanation: