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: Medicine
[{'content': 'All can be used as endoscopic sclerosants in the treatment of variceal bleeding, except - \nSelect and explain. \nA. Polydochyl, B. Cynoaciylate, C. Alcohol, D. Acetic acid', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]