Refer to the exhibit. Cisco Unified CallManager cluster A and Unity A use extension range 1000-1650. Cisco Unified CallManager cluster B and Unity B use extension range 2000-2450. Cisco Unified CallManager cluster C and Unity C use extension range 1500-1950. 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.
Which statement is true?

A.
All Cisco Unity servers are in different locations, but are part of the same dialing domain.

B.
A unique dialing domain is created per Cisco Unity location. The other Cisco Unity locations are automatically available at that time.

C.
All Cisco Unity servers are in the same dialing domain, and Cisco Unified CallManager cluster C needs to change the extensions that overlap with Cisco Unified CallManager cluster A.

D.
Cisco Unity servers A and B are in the same dialing domain and Unity C is put into its own dialing domain to address the extension conflicts with Unity A and B.