This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'Vaccine which requires stringent condition for storage \nSelect and explain. \nA. DPT, B. OPV, C. BCG, D. TT', 'role': 'user'}, {'content': "Answer: B \nExplanation: (Refer: K. Park's Textbook of Preventive and Social medicine, 24th edition, pg no: 222)", 'role': 'assistant'}]