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': 'Which is C/I in closed system anesthesiology : \nSelect and explain. \nA. Methoxyflurane, B. Isoflurane, C. Sevoflurane, D. Desflurane', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Sevoflurane', 'role': 'assistant'}]