Which statement is true about PIM?

PIM Sparse Mode (PIM-SM) is designed for environments where multicast receivers are sparsely distributed, meaning receivers must explicitly join a multicast group. It utilizes a shared tree (RPT - Rendezvous Point Tree) rooted at a Rendezvous Point (RP) to initially forward multicast traffic from sources to all receivers that have joined the group through the RP.

In Bidirectional PIM (Bidir-PIM), sources do not register to the RP; traffic simply flows bidirectionally along a shared tree without explicit source registration.

The PIM Dense Mode (PIM-DM) flood and prune process typically involves prune states timing out after three minutes, not five minutes, after which flooding can resume.

While PIM-SM uses the shared tree initially, the last-hop router connected to a receiver can optionally switch to a shortest-path tree (SPT) directly to the source for more optimal and efficient traffic forwarding.