This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'The most effective vaccine is - \nSelect and explain. \nA. TT, B. OPV, C. B.C.G, D. Measles', 'role': 'user'}, {'content': 'Answer: D \nExplanation: .most effective vaccine is the live attenuated vaccines for measles.it is presented as afreeze dried product.0.5 ml contains more than 1000 vral infective units of the vaccine strain.uually given after 9 months of age along with vit A prophylaxis as per national immunisation schedule. ref:park&;s textbook,ed 22,pg no 140', 'role': 'assistant'}]