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': 'Methotrexate is what class of anti cancer drug ? \nSelect and explain. \nA. Alkylating agents, B. Antimetabolites, C. Microtubule damaging agents, D. Topoisomerase inhibitors', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Antimetabolites", 'role': 'assistant'}]