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: Pediatrics
[{'content': 'Posterior urethral valve is diagnosed on micturating cystometrogram by : \nSelect and explain. \nA. Dilatation of posterior urethra, B. Bladder neck contracture, C. Vesico-Ureteric reflex, D. Bladder wall hypertrophy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Micturating cystourethrogram findings :\n\nDilation of prostatic urethra.\nTransverse linear filling defect corresponding to the valves.', 'role': 'assistant'}]