This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'Duration of apnea in OSAS is \nSelect and explain. \nA. > 10 seconds, B. > 20 seconds, C. > 30 seconds, D. > 60 seconds', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]