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
After doing a graft repair 'of a thoracoabdominal aneurysm, the patient developed weaknesss in both legs. Most probable cause for this is: 
Select and explain. 
A. Decreased blood supply to the lower limbs, B. Thoracosplanchnic injury, C. Discontinuation of arteria radicularis magna, D. Lumbosacral nerve injury
C: Discontinuation of arteria radicularis magna
Answer: C: Discontinuation of arteria radicularis magna 
Explanation: None