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: Surgery
[{'content': 'Agents used for sclerotherapy in varicose veins are all except \nSelect and explain. \nA. Ethanolamine oleate, B. Sodium tetradecyl sulphate, C. Polidocanal, D. Mannitol', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Mannitol is not a sclerosing agent.', 'role': 'assistant'}]