An administrator is implementing a multicast solution in a multi-VLAN network. Which statement is true about the configuration of the switches in the network?

A. IGMP snooping must be enabled on all interfaces on a switch to intelligently forward traffic

B. IGMP requires join and leave messages to graft and prune multicast streams between switches

C. IGMP must be enabled on all routed interfaces where multicast traffic will traverse

D. IGMP must be enabled on all interfaces where multicast sources and receivers are connected