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: Anatomy
Ala of sacrum is not crossed by 
Select and explain. 
A. Sympathetic chain, B. Iliolumbar aery, C. Obturator nerve, D. Ureter
D: Ureter
Answer: D: Ureter 
Explanation: Ans. is 'd' i.e., UreterThe smooth medial pa of the ala of sacrum is associated with the subsequent 4 structures from medial to lateral side: 1. Sympathetic chain. 2. Lumbosacral trunk. 3. Iliolumbar aery. 4. Obturator nerve.The ventral ramus of L5 nerve is really tight that it grooves the ala.The rough lateral pa of the ala provides origin to iliacus muscle anteriorly and connection to the lumbosacral ligament posteriorly.