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 which surrounds the aorta has its two limbs split by - \nSelect and explain. \nA. Left renal vein, B. Left renal artery, C. Isthumus of horseshoe kidney, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: • The main renal vein divides and sends one limb anterior and another limb posterior to aorta to reach the IVC.\n• Formed on the left side\xa0and represents persistence of the embryonic state.', 'role': 'assistant'}]