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 narrowest valvular pa of ureter is: \nSelect and explain. \nA. At pelvic brim, B. At ischial spine, C. Pelvic ureteric junction, D. At the entry of bladder', 'role': 'user'}, {'content': 'Answer: D \nExplanation: At the entry of bladder', 'role': 'assistant'}]