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 the 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 part of duodenum, C. Aorta, D. Right ureter', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Attached border of mesentery (the root of mesentery) crosses -\n\n\nThird (horizontal) part of the duodenum\nAbdominal aorta\nIVC\nRight ureter\nRight psoas major', 'role': 'assistant'}]