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: Anaesthesia
[{'content': 'O2 is given during anaesthesia to prevent – \nSelect and explain. \nA. Pain, B. Hypoxia, C. Hypercapnia, D. Hypotension', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]