When the multicast source starts to send multicast data and no receiver joins in the RP in PIM-SM, which of the following statements are true?
A . The RP receives a registration message from the source DR, creates a multicast routing entry (S, G), and sends a register stop message to the source D
C . After the source DR unicasts registration information to the RP, the multicast routing entries (S, G) of all source groups are generated in the RP but the outbound interface is null.
D . After receiving a registration message, the RP creates the multicast routing entries (*, G) of all source groups and sends a register stop message to the source D
F . After all sources unicast registration information to the RP, no multicast route entries related to source groups are generated due to receiver absence.
Answer: A, B