which technology supports Multi Chassis EtherChannel in the design of a network?

Refer to the exhibit.

A new IPv4 multicast-based video-streaming service is being provisioned. During the design- validation tests, you realize that the link between the two buildings is carrying multicast traffic even when there are no receivers connected to the switch in Building B and despite IGMP snooping being enabled on both Layer 2 switches and IGMPv2 runs on the hosts. Which design change will prevent the multicast traffic from being unnecessarily flooded throughout the campus network?

Refer to the exhibit.
This Layer 2 network is expected to add 150 VLANs over the next year, in addition to the existing 50 VLANs within the network. Which STP type will support this design requirement using the least amount of CPU resources and achieving load-balancing?

Which solution prevents microloops from being formed during network convergence time?

In which two ways is IPv4 and IPv6 traffic handled in a network design that uses QoS deployment options?
(Choose two.)