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: Social & Preventive Medicine
[{'content': 'DPT vaccine is stored at what temperature (in °C)? \nSelect and explain. \nA. 4-Feb, B. 8-Apr, C. 0, D. -20', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]