What could be the source of the problem when you encounter a situation where a 7960 IP phone with 7914 attached registers to Cisco CME, Extensions appear on 7960, but extension numbers on 7914 do not appear.
A.
A separate undefined ephone for 7914.
B.
There’s an authentication failure during auto-registration.
C.
The phone type for 7914 has not been defined under ephone.
D.
Undefined username and password under ephone.