A large Enterprise is using an Avaya Aura® Core. An Avaya SIP Endpoint, one-X® Communicator, controlled by Avaya AuraÂ

[answerhappygod]

A large Enterprise is using an Avaya Aura® Core. An Avaya SIP Endpoint, one-X® Communicator, controlled by Avaya Aura® Communication Manager (CM), has been configured with three feature buttons, but none of the buttons appear on the telephone interface. The telephone shows successful registration with
Avaya Aura® Session Manager (SM) at the SIP Level.
What is the cause of this problem?

A. The SM Server is down.
B. The SIP Signaling Group between SM and CM is down.
C. The telephone is pointing to CM instead of SM for registration.
D. CM has no DSP Resources available.
E. The Application Sequence for CM has not been selected for that extension in SM.