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': 'Which among the following is live attenuated vaccine \nSelect and explain. \nA. OPV, B. DT, C. TAB, D. TT', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans) a (OPV) Ret Park 20th ed p 180Another simple question regarding immunization.OPV is a live attenuated vaccine. DT and TT are toxoidTAB is a heat killed Typhoid bacillus vaccine', 'role': 'assistant'}]