Dubs of Radio Commercials Are Created

Dubs of radio commercials are created:

A) as audio storyboards for advertisers.
B) in the postproduction phase of radio commercial production.
C) as a form of speculative presentation during the commercial bidding process.
D) as the special effects that are superimposed on the radio commercial once the copy has been read.
E) to measure the master volume of the commercial.