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: Physiology
[{'content': 'At what temperature blood is stored: \nSelect and explain. \nA. —4°C, B. 4°C, C. 6°C, D. 8°C', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]