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
The mesentery of the small intestine, along its attachment to the posterior abdominal wall, crosses all of the following structures except - 
Select and explain. 
A. Left gonadal vessels, B. Third part of duodenum, C. Aorta, D. Right ureter
A: Left gonadal vessels
Answer: A: Left gonadal vessels 
Explanation: Attached border of mesentery (the root of mesentery) crosses -


Third (horizontal) part of the duodenum
Abdominal aorta
IVC
Right ureter
Right psoas major