Users of your local Cisco Unified Communications Manager cluster report that they receive error "Login is unavailable (23)" when they try to log in to Extension Mobility. Which reason for this error is true?

A.	User provided the wrong UserID or PIN
B.	User has no Extension Mobility profiles assigned.
C.	The given user ID is not found any of the remote clusters.
D.	Phone is not subscribed to Extension Mobility phone service.