This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'An antimetabolite which undergoes biotransformation to form an inhibitor of DNA polymerase is - \nSelect and explain. \nA. Vinablastine, B. Cytosine arabinoside, C. Methotrexate, D. Chlorambucil', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Cytosine arabinosideo Cytarabine is phosphorylated in the body to the corresponding nucleotide which inhibits DNA synthesis by inhibiting DNA polymerase.", 'role': 'assistant'}]