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': 'Mode of action of azathioprine ? \nSelect and explain. \nA. | IL-2, B. T-cell blockade, C. Decreased lymphophagocytic activity, D. Wide-spread antitumor activity', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., T-cell blockade", 'role': 'assistant'}]