This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Female & male reproductive system, rectum and anal canal, Subject name: Anatomy
[{'content': 'A 49-year-old woman has a large mass on the pelvic brim. Which of the following structures is most likely compressed by this mass when crossing the pelvic brim? \nSelect and explain. \nA. Ovarian Aery, B. Uterine tube, C. Ovarian ligament, D. Lumbosacral trunk', 'role': 'user'}, {'content': 'Answer: D \nExplanation: All of the listed structures do not cross the pelvic brim except the lumbosacral trunk. It arises from L4 and L5, enters the true pelvis by crossing the pelvic brim, and contributes to the formation of the sacral plexus.', 'role': 'assistant'}]