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': 'Risk factor for bladder carcinoma is \nSelect and explain. \nA. Clonorcis sinensis, B. Schistosoma hematobium, C. Plasmodium, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer- B. Schistosoma hematobiumCigarette smoking is the main etiological factor.Occupational exposures to chemicalsSchistosoma haemotobiumDrugs such as phenacetin & chlornaphazineCyclophosphamidetherapyPelvic radiation', 'role': 'assistant'}]