Which two locations are the best locations that an end user can use to determine if an IP phone is working in SRST mode?

Which two locations are the best locations that an end user can use to determine if an IP phone is working in SRST mode? (Choose two)

A.
Cisco Unified Communications Manager Administration

B.
IP phone display

C.
Cisco Unified SRST Router

D.
Cisco Unified MGCP Fallback Router

E.
physical IP phone settings

Explanation:
Ok, end-user reference