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: Gynaecology & Obstetrics
[{'content': 'A 55 year old woman has recurrent urinary retention after a hysterectomy done for a huge fibroid. The most likely cause is : \nSelect and explain. \nA. Atrophic and stenotic urethra, B. Lumber disc prolapse, C. Injury to bladder neck, D. Injury to hypogastric plexi', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Injury to hypogastric plexi', 'role': 'assistant'}]