This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hydramnios and Oligo Hydramnios, Subject name: Gynaecology & Obstetrics
[{'content': "Cryptomenorrhea is seen in: \nSelect and explain. \nA. Asherman's syndrome, B. Testicular feminizing syndrome, C. Imperforate hymen, D. Uterine agenesis", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. Imperforate hymenCryptomenorrhea means monthly subjective symptoms of menstruation without flow of blood and may be caused by an imperforate hymen. Crypt literally means hidden- Thus cryptomenorrhea means hidden menorrhea.', 'role': 'assistant'}]