System A at Company 1 is calling System B at Company 2. The call completes, but only audio and video are present on System A from System B. What are three possible causes? (Choose three.)

System A at Company 1 is calling System B at Company 2. The call completes, but only audio and video are present on System A from System B. What are three possible causes? (Choose three.)
A . System A cannot call System B because it is at a different company.
B . There is a firewall in the path that is blocking audio and video traffic from Company 1 to Company 2.
C . The firewall at Company 1 is blocking outgoing traffic.
D . An access list is blocking video and audio somewhere in the video and audio path between System A and System
F . System A has turned off the camera and the microphone.

Answer: B,D,E