Exam 300-510 topic 1 question 91 discussion

I think B, it doesnt make much sense that you would add "ip igmp static-group" to ALL interfaces

"If the router has the ip igmp join-group command on any of the interfaces, the router itself becomes a receiver for the multicast stream. This command is used in order to move multicast traffic to this router without a real directly-connected receiver or without a Protocol Independent Multicast (PIM) neighbor downstream that sends PIM Join requests for the multicast flow. However, because this router joins the multicast stream, all of the multicast packets are punted to the CPU. This can cause high CPU, or it can cause the rate-limiters (if any) or the Control Plane Protection (CoPP) to be hit. A better alternative that you can use in order to attract the multicast stream for this router is to configure the ip igmp static-group interface command. With this command, the router can still attract the multicast stream and forward it out on the interface, but the router itself does not become a receiver for the stream."

You shouldn't use "ip igmp join-group" command in production, maybe only for test purpose as then all multicast packets are punted to the CPU. Better alternative command is " ip igmp static-group" So my option is D