Which two statements about the functionality of a gatekeeper are true? (Choose two.)
A. Cisco Unified Communications Manager has gatekeeper functionality built in.
B. Cisco Unified Communications Manager registers with a gatekeeper via SIP.
C. Cisco Unified Communications Manager registers with a gatekeeper via H.323.
D. A gatekeeper can enable CAC and AAR.
E. A gatekeeper can enable CAC, but not AAR.
