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: Social & Preventive Medicine
[{'content': 'Most heat sensitive vaccine- \nSelect and explain. \nA. BCG, B. TT, C. OPV, D. Small pox', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., OPV", 'role': 'assistant'}]