单项选择题
A.RP B.multicast source C.IGMP router D.multicast receiver E.PIM designated router
A.5 seconds and 3 retries B.10 seconds and 5 retries C.10 seconds and 3 retries D.20 seconds and 5 retries E.5 seconds and 5 retries
A.3 B.4 C.5 D.2 E.6