Refer to the exhibit. What is the cause of the ISSU failure when using the command show system internal csm global info?
A. The command conf-t is holding a lock and not released it.
B. The SSN feature is not enabled on both switches.
C. The reference count is less than 1 due to a lack of successful config-sync.
D. It cannot be determined from the output.
E. An Administrator is logged in on another session and has a lock of the session data base to prevent ISSU.
