Which two methods can be used to build a SIP trunk from the Cisco Unified CallManager to a SIP Registrar server and a backup Registrar server? (Choose two.)
A.
Configure one SIP trunk to point to the SIP Registrar server and a second SIP trunk to point to the backup Registrar server. Use route groups and a route list to allow calls to be routed to the backup Registrar if the primary does not respond.
B.
Add the SIP Registrar server and the backup Registrar server to the Device Pool assigned to the SIP trunk.
C.
Configure a DNS SRV record name as the destination address of the SIP trunk.
D.
Configure only the SIP Registrar Server in the SIP trunk; The UA message will include the IP address of the backup SIP trunk if the call cannot be set up by the SIP Registrar server.
E.
Configure the IP address of the SIP Registrar server as the first destination address of the trunk and the IP address of the backup Registrar server as the second destination address.
Explanation: