What is the cause of the drop in video?

A corporation has a Cisco Unified Wireless Network that has been deployed for voice coverage. The wireless data rates have been tuned to mandatory rates of 18 Mbps and 36 Mbps. Some wireless clients have been experiencing drops streaming multicast video while moving throughout the building.

What is the cause of the drop in video?
A . Clients are maintaining a 12Mbps rate and cannot receive the stream at 18Mbps.
B . Clients are not roaming due to coverage. This is causing the multicast data to drop due to the client reassociating often.
C . Clients are roaming at lower data rates and are not maintaining 36Mbps connectivity.
D . Clients are connected at 18Mbps; however, other clients are connecting at 12Mbps and are causing the multicast video to degrade.

Answer: C