This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Congenital malformations, Subject name: Gynaecology & Obstetrics
[{'content': 'Emergency presentation of imperforate hymen is \nSelect and explain. \nA. Retention of urine, B. Mass abdomen, C. Cyclic pain, D. Hematocolpos', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Imperforate hymen present with Amenorrhea with secondary sexual characters Cyclical abdominal discomfo Retention of urine Palpation of midline hypogastric lump Ref: Shaw Gynecology 17 e pg 67.', 'role': 'assistant'}]