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': 'Pin code index of N2O is – \nSelect and explain. \nA. 1,6, B. 2,5, C. 2,6, D. 3,5', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]