How does PIM build the IP multicast routing table to route traffic between a multicast source and one or more receivers9

How does PIM build the IP multicast routing table to route traffic between a multicast source and one or more receivers9
A . It uses IGMP and calculates a shortest path tree (SPT).
B . It uses the shortest path first (SPF) algorithm derived from link state protocols.
C . It uses the Bellman-Ford algorithm derived from distance vector protocols
D . It uses the unicast routing table and reverse path forwarding (RPF )

Answer: D