C (PIM Sparse Mode with RP located at the hub):DMVPN networks typically leverage sparse mode multicast due to their efficiency in dynamic topologies. Locating the Rendezvous Point (RP) at the hub simplifies multicast state management, since the hub serves as the central aggregation point and ensures optimal rendezvous functionality without requiring complex RP placement across spokes.

Other options explained:

A: Dense mode is inefficient and generates unnecessary flooding, especially in WAN environments.

B/D: Placing RPs at remote sites introduces unnecessary complexity and operational challenges.