In the Ames Test for Mutagenicity,rat Liver Enzymes Are Included

In the Ames test for mutagenicity,rat liver enzymes are included with the compound under test because

A) bacterial cell walls must be treated to permit uptake of the compounds.
B) rat liver enzymes increase the sensitivity of the bacteria to mutagens.
C) rat liver enzymes kill mutant cells and allow colonies to form.
D) rat liver enzymes may modify or break down some harmless compounds to produce mutagens.
E) the mutant strain of bacteria requires rat liver enzymes to digest nutrients for growth.