There Was an Extensive Black Market (Illegal Market) for Many

There was an extensive black market (illegal market) for many consumer products in the United States during the Second World War. A likely explanation of the black market is that:

A) the prices of goods were artificially held down by price controls.
B) black markets were legal during the war.
C) goods were not subject to price controls.
D) gasoline rationing greatly restricted civilians from driving to stores.