What is the effect of a multipoint control unit service prefix on the function of the VCS?

A.
The VCS will only search neighbor zones that have the multipoint control unit service prefix in their configuration

B.
The VCS will always search neighbor zones if a prefix is induded

C.
The VCS will route all calls beginning with the prefix to the multipoint control unit

D.
The service prefix will be added to all VCS registrations