This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous General Anesthesia, Subject name: Anaesthesia
[{'content': 'Anaesthetic agent not metabolized by body is? \nSelect and explain. \nA. N20, B. Gallamine, C. Sevofluorane, D. Halothane', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) N20Ref: Miller's 7thedch: 24", 'role': 'assistant'}]