This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': 'The following is a killed vaccine \nSelect and explain. \nA. Varicella, B. BCG, C. OPV, D. Meningococcal vaccine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Peussis, meningococcal, Salk, cholera, rabies, influenza are killed vaccines BCG OPV are live attenuated vaccines Ref: Textbook of Microbiology Baveja 4th ed Pg 617', 'role': 'assistant'}]