Which two options enable routers to provide basic call handling support for Cisco Unified IP Phones
if they lose connection to all Cisco Unified Communications Manager systems? (Choose two.)

A.
SCCP fallback

B.
Cisco Unified Survivable Remote Site Telephony

C.
Cisco Unified Communications Manager Express

D.
MGCP fallback

E.
Cisco Unified Communications Manager Express in SRST mode