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': 'All are precancerous for carcinoma bladder except - \nSelect and explain. \nA. Tuberculosis bladder, B. Aniline dyes, C. Schistosomiasis, D. All', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e. Tuberculosis bladder", 'role': 'assistant'}]