This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'Drug of choice for surgically unresectable renal cell carcinoma is ? \nSelect and explain. \nA. Sorafenib, B. Sunitinib, C. Imatinib, D. Cetuximab', 'role': 'user'}, {'content': 'Answer: B \nExplanation: .', 'role': 'assistant'}]