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': "After doing a graft repair 'of a thoracoabdominal aneurysm, the patient developed weaknesss in both legs. Most probable cause for this is: \nSelect and explain. \nA. Decreased blood supply to the lower limbs, B. Thoracosplanchnic injury, C. Discontinuation of arteria radicularis magna, D. Lumbosacral nerve injury", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]