Refer to the exhibit. Cisco Unified CallManager cluster A and Unity A use extension range 1000-
2500. Cisco Unified CallManager cluster B and Unity B use extension range 3000-3450. Cisco
Unified CallManager cluster C and Unity C use extension range 4200-4400. Your customer wants
to deploy Unified Messaging. Exchange stores are local at each site and part of the same
organization. Digital networking without using access codes is an absolute requirement, and
callers need to be able to use the Cisco Unity Auto Attendant to reach any user at any site.
Which statement is true?

A.
All Cisco Unity servers will recognize each other via Active Directory. The Cisco Unified
CallManager will handle any overlapping dial plan with partitions and calling search spaces.

B.
Cisco Unity servers A and B are in the same dialing domain and Cisco Unity C uses extension
masking to address any extension conflicts with them.

C.
Configure all Cisco Unity servers into the same dialing domain and each Cisco Unity call
handler search scope to that dialing domain.

D.
To deploy Unified Messaging, you need three separate dialing domains.

Explanation: