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': 'Renal collar to prevent spread of malignancy from kidney is put around - \nSelect and explain. \nA. Aorta, B. IVC, C. Renal vein, D. Renal artery', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]