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': "Painless gross hematuria occurs in \nSelect and explain. \nA. Renal cell carcinoma, B. Polycystic kidney, C. Stricture of urethra, D. Wilm's tumor", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]