When Used in Reference to Producing a Radio Commercial, the Term

When used in reference to producing a radio commercial, the term "board" refers to the:

A) group of people who are brought together during the preproduction phase of a commercial.
B) final recording of the ad before it is duplicated on dubs.
C) equipment for recording and channeling sounds to the appropriate recording devices.
D) place where the sound engineer sits to control the sounds generated in the sound studio.
E) group of creatives that is responsible for editing the finished commercial.