This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
Which of the following is an Antimetabolite 
Select and explain. 
A. Methotrexate, B. Cyclosporine, C. Etoposide, D. Vinbalstine
A: Methotrexate
Answer: A: Methotrexate 
Explanation: Refer KDT 6/e p 823 Methotrexate is an Antimetabolite that acts By inhibiting DHFRase