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 is \nSelect and explain. \nA. Polio, B. BCG, C. Measles, D. DPT', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Most Thermolabile vaccine: Reconstituted BCG\nMost Thermostable vaccine: TT', 'role': 'assistant'}]