In multicast network environment, if IGMPv2 hosts and IGMPv1 routers (hereinafter referred to as version 2 host and version 1 router) are co-located on the same LAN, how do they work together?
A . version 1 router treats the IGMPv2 report as an invalid IGMP message type and ignores it.
B . When version 1 router is a valid IGMP querier, the version 2 host must send an IGMPv1 report.
C . When Version 2 host detects that the IGMP Querier is Version 1 router, it must always respond with the IGMPv1 report.
D . When version 2 host leaves, it still sends an IGMP leave message, and the message can’t be suppressed.