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: Surgery
[{'content': 'Most common cause of hydronephrosis in children \nSelect and explain. \nA. Ureterocoele, B. Ureteric stricture, C. Watermelon prostate, D. Congenital PUJ obstruction', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Congenital PUJ obstruction is MCC for hydronephrosis in children.', 'role': 'assistant'}]