Some Cisco Unity Unified Messaging users complain that they cannot make a TRaP connection when attempting to play and record messages through their desktops. What is a possible cause of this?

A.
A firewall separates these users from Cisco Unity.

B.
These users are not licensed for Unified Messaging.

C.
These users need to have their Exchange mailboxes modified to allow access.

D.
The Cisco Unity server does not have a sufficient number of Unified Messaging licenses.