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': 'A Most common tumor of the urinary bladder is - \nSelect and explain. \nA. Sq. cell carcinoma, B. Adeno carcinoma, C. Transitional carcinoma, D. Str. squamous carcinoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: There are 3 common histological types of bladder cancer \n\nTransitional (urothelial) cell ca - ~90%\nSquamous cell ca - ~5-10%\nAdenocarcinoma - ~2%', 'role': 'assistant'}]