An Engineer Must Configure an MGCP Gateway and Register It

An engineer must configure an MGCP gateway and register it to Cisco Unified Communications Manager. Which prerequisite must be met before applying the gateway commands to enable MGCP?

A) The MGCP gateway and the Cisco Unified CM must be able to communicate aver ports 5060 and 5061.
B) Cisco Unified CM and the MGCP gateway must utilize the SIP OPTIONS ping feature to monitor status.
C) The MGCP gateway must have voice service VoIP configured.
D) The MGCP gateway and the Cisco Unified CM must be able to communicate over ports 2427, 2428, and 2727.