Which step will determine the cause of the problem?

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.