What is the role of the RP in PIM sparse mode?

A.	The RP maintains default aging timeouts for all multicast streams requested by the receivers.
B.	The RP acts as a control-plane node only and does not receive or forward multicast packets.
C.	The RP is the multicast router that is the root of the PIM-SM shared multicast distribution tree.
D.	The RP responds to the PIM join messages with the source of a requested multicast group.