Company Ciscoexam just completed an upgrade of the Cisco Unified Communications Manager from version 9.x to version 10.5. Users report that they cannot log in to Extension Mobility after the upgrade. This error message is displayed "login is unavailable (23)". Which action can resolve the issue?

A.	Cisco Unified Communications Manager 10.5 does not include Extension Mobility.
B.	Enable the home cluster option for the affected users.
C.	Re-enable extension mobility for the affected users.
D.	Enable the remote cluster option for the affected users.