The following statements about PIMSSM are correct

The following statements about PIMSSM are correct
A . To be compatible with the earlier version of IGMP, the receiver in PIMSSM also uses IGMP V2 to send join messages
B . PIMSSM can be simply viewed as similar to PIMSM. After the host sends a join message, the device sends a (*, G) join message to the multicast source
C . The multicast packet reaches the receiver along the SPT between the multicast source and the receiver
D . Compared with PIMSM, PIMSSM does not require RP, which improves message forwarding efficiency

Answer: CD