When using redundant Cisco Unified IP IVR systems for queuing in the Cisco Unified Contact Center Enterprise solution, which of these statements must be true?

A.
The pair of Cisco Unified IP IVRs must be deployed using the Cisco Unified IP IVR high-availability
option.

B.
Each Cisco Unified IP IVR must be pointed to a different subscriber in the Cisco Unified Communications Manager cluster.

C.
Both Cisco Unified IP IVRs must use the same resource manager JTAPI and CRS JTAPI users when connecting to the Cisco Unified Communications Manager cluster.

D.
The private network between the duplex Cisco Unified IP IVRs must have QoS applied for both Layer 2 and Layer 3 markings.