Refer to the exhibit. You are trying to establish a multipoint call via a Cisco TelePresence SX20 that is registered to Cisco Unified Communications Manager. When you attempt to bring a third party into the call, you receive an error that the call cannot be completed. You confirm that your MCU resources are configured correctly on Cisco Unified Communications Manager and that other devices are able to establish multipoint calls. What is the cause of this issue?
A. The multipoint mode should be set to Multiway.
B. The call protocol should be H.323.
C. The MCU is at capacity.
D. The multipoint mode should be set to Cisco Unified Communications Manager Resource Group.
E. The multipoint mode should be set to None.
