Which of the following is NOT a reason why viral enzymes make good targets for the development of antiviral drugs?

A) Enzymes inhibitors bind more tightly to their targets than inhibitors of other proteins.
B) Drug companies have experience designing enzyme inhibitors.
C) Enzymes normally interact with small molecules.
D) Enzymes are usually well understood mechanistically.
E) Enzymes are present in low concentrations within the infected cell.