When building an IP multicast domain using PIM which mode assumes that other routers do not want to forward multicast packets for the group?

When building an IP multicast domain using PIM which mode assumes that other routers do not want to forward multicast packets for the group?

A.
PIM-DM

B.
PIM-SM

C.
PIM-RP

D.
CGMP

E.
IGMP snooping