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: ENT
[{'content': 'Definition of sleep apnoea \nSelect and explain. \nA. >10 apnoeas during 7 hours of sleep, B. >30 apnoeas during 7 hours of sleep, C. >10 apnoeas during 2 hours of sleep, D. >30 apnoeas during 2 hours of sleep', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]