Which protocol can operate in both dense mode (DM) and sparse mode (SM)?

The chosen answer is PIM (Protocol Independent Multicast), which is indeed capable of operating in both dense mode (DM) and sparse mode (SM). PIM is a multicast routing protocol designed to efficiently route data to multiple recipients. Its flexibility allows it to adapt to different network environments—dense mode is often used in networks where multicast group members are concentrated in a small area, while sparse mode is used when members are distributed across a wider geographical area.

By using PIM, a network can effectively handle multicast traffic regardless of the distribution of the receivers. In dense mode, PIM uses a flood-and-prune mechanism to send multicast traffic to all potential recipients initially, then prunes back the branches where there are no group members. In sparse mode, it relies on explicit Join requests from receivers and uses a shared tree or source tree to manage traffic delivery, reducing unnecessary load on the network.

In contrast, the other protocols listed do not share this dual-mode capability. IGMP (Internet Group Management Protocol) is primarily concerned with managing membership in multicast groups rather than routing. DVMRP (Distance Vector Multicast Routing Protocol) is designed mainly for dense mode environments and does not facilitate sparse mode operation effectively. OSPF (Open Shortest