Which function does BFCP provide?

Which function does BFCP provide?
A . BFCP is a secondary video channel that is used for content such as slide presentations and desktop sharing.
B . BFCP is used to determine who is allowed to send media to the content channel.
C . BFCP provides the ability to pan, tilt, and zoom the far end’s camera.
D . BFCP negotiates who can send DTMF tones and when the tones are sent.

Answer: B