A new Cisco Unity subscriber notifies the administrator that MWIs are not being turned on or off at their telephone. On further investigation, the subscriber notes that on occasion, the MWI light on the phone flashes briefly and then goes out again.
What is the most likely cause of the problem?

A.
The MWI light on the telephone has a broken contact.

B.
There are not enough ports dedicated to turning MWIs on and off.

C.
The MWI codes listed in the Unity Telephony Integration Manager (UTIM) are incorrect

D.
The user has set up a rule in their Outlook Inbox that moves all voice mail to another folder.