Dihydrofolate Reductase and Thymidylate Synthetase Are Major Targets for Anticancer

Dihydrofolate reductase and thymidylate synthetase are major targets for anticancer drugs because

A) these enzymes are unique in cancer cells.
B) cancer cell grow rapidly and are very dependent upon the activities of these enzymes.
C) they donate one-carbon groups.
D) cancer cells lack sufficient amounts of these enzymes.
E) All of the above