This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Surgery
[{'content': 'Urinary retention in child is most commonly caused by \nSelect and explain. \nA. Metal scab with ulceration, B. Posturethral valve, C. Urethral stricture, D. Epispadius', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (A) Metal scab with ulceration # Acute urinary retention in a male child may be due to local inflammatory causes like meatal ulcer with scabbing.> Etiology of Urinary Retention in Children: Neurological processes Severe voiding dysfunction UTI Constipation Adverse drug effect Local inflammatory causes Locally invading neoplasms Benign obstructing lesions Idiopathic Combined UTI and Constipation Incarcerated Inguinal Hernia.', 'role': 'assistant'}]