How does the Cisco IP phone in a branch office know which device will be running SRST when there is a WAN outage?

A.
The phone uses the IP address configured for failover.

B.
The phone needs to have the device’s IP address in the CCM.

C.
The SRST device sends its IP address to the phone when there is a WAN outage.

D.
All routers at the branch site run SRST so the phone randomly selects a router to fail to.