Which protocol is used by the Cisco TelePresence Multipoint Switch to instruct Cisco TelePresence endpoints to stop transmitting video during an active multipoint call?

Which protocol is used by the Cisco TelePresence Multipoint Switch to instruct Cisco TelePresence endpoints to stop transmitting video during an active multipoint call?

A.
RTSP

B.
RTCP

C.
SIP

D.
H.323