What is a prerequisite of AAR deployment?

A.	You must have a single distributed call processing deployment.
B.	Calls must be manually rerouted through the PSTN or other networks when Cisco Unified Communications Manager blocks a call due to insufficient location bandwidth.
C.	Calls must be automatically rerouted through the PSTN or other networks when Cisco Unified Communications Manager blocks a call due to insufficient location bandwidth.
D.	Clustering must be implemented over the WAN.
E.	You must have a centralized call processing deployment.