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
[{'content': 'The mesentery of small intestine, along its attachment to the posterior abdominal wall, crosses all of the following structures except: \nSelect and explain. \nA. Left gonadal vessels, B. Third pa of duodenum., C. Aoa, D. Right ureter.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Left gonadal vesselsRoot of mesentery crosses (successively) te ascending (4th) and inferior horizontal (3rd) pas of duodenum, abdominal aoa, IVC, right ureter, right psoas major and right gonadal (testicular/ovarian) vesselQ. It does not cross left ureter, leftgonadal vessels and superior mesenteric vessels.', 'role': 'assistant'}]