As administrator replaced a faulty IP phone with a new one by replacing the hardware and editing the phone MAC address in the device configuration in Cisco Unified Communications Manager. When the administrator tries to the save the configuration, the old MAC address still appears under the device configuration. What is the most likely cause of this issue?
A. The administrator does not have full access privileges in Cisco Unified Communications Manager.
B. The administrator must edit the new phone MAC address under the Phone Enterprise settings page.
C. The Cisco Unified Communications Manager needs to be enabled for autoregistration.
D. The subscriber the phone is registered to may have database replication issues.
E. The MAC address for the new IP phone must be configured in the publisher instead of the subscriber.
