This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'Bilateral hydroureteronephrosis is usually the result of \nSelect and explain. \nA. Posterior urethral valves, B. Urethral stricture, C. Benign prostatic hyperplasia, D. Bilateral renal calculi', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Only bilateral ureteric calculi cause hydroureteronephrosis', 'role': 'assistant'}]