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: Microbiology
[{'content': 'Which of the following is live attenuated vaccine: \nSelect and explain. \nA. Salk polio vaccine, B. Sabin polio vaccine, C. Rabies vaccine, D. KFD vaccine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. b. Sabin polio vaccine', 'role': 'assistant'}]