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
When a horseshoe kidney develops, the ascent of the kidney is restricted by the 
Select and explain. 
A. Internal iliac aery, B. External iliac aery, C. Common iliac aery, D. Inferior mesenteric aery
D: Inferior mesenteric aery
Answer: D: Inferior mesenteric aery 
Explanation: A horseshoe kidney develops when the inferior poles of the two kidneys fuse together as they ascend into the abdomen from the pelvis. The first anterior midline vessel that is encountered by the horseshoe kidney is the inferior mesenteric aery. This aery prevents the kidney from continuing its ascent.