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 of the following anaesthetic agents has the least analgesic effect? \nSelect and explain. \nA. N2O, B. Ether, C. Halothane, D. Cyclopropane', 'role': 'user'}, {'content': 'Answer: C \nExplanation: N2O is a potent analgesic but not a potent anesthetic. Halothane is a good anaesthetic but poor analgesic.', 'role': 'assistant'}]