A network engineer needs to configure multicast in the network. The implementation will use multiple multicast groups and PIM routers. Which address provides automatic discovery of the best RP for eac

224.0.0.13 is the ALL-PIM-ROUTERS multicast address used for PIM hello, join, and prune messages, not for RP discovery.

224.0.0.14 is assigned to RSVP-ENCAPSULATION and has no role in PIM or multicast RP selection.

224.0.1.39 is the Auto-RP Announce address used by candidate RPs to advertise themselves to the RP Mapping Agent - the upstream direction of Auto-RP, not the discovery distribution to routers.

224.0.1.40 is the Auto-RP Discovery address used by the RP Mapping Agent to distribute RP-to-group mappings to all PIM routers in the domain. All PIM routers listen to this address to dynamically learn which RP handles which multicast group ranges, enabling automatic RP selection without manual configuration. This is the address that fulfills the 'automatic discovery of the best RP' requirement.