This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Normal Menstruation, Abnormal Menstruation, Menopausal Physiology and forsight of conception, Subject name: Gynaecology & Obstetrics
[{'content': 'A lady with secondary amenorrhea is negative for progesterone challenge test but positive for combined estrogen and progesterone challenge test. What is the probable cause:- \nSelect and explain. \nA. Ovarian failure, B. PCOD, C. Asherman syndrome, D. Pregnancy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: PCOS has plenty estrogens but no progesterones, hence Progesterone therapy will elicit a withdrawal bleeding Asherman Syndrome is Endometrial Fibrosis, hence no estrogen or progesterone will show any effect In Pregnancy , if Estrogen and progesterones are given, it will not cause a withdrawal since the patient herself is making adequate amount of those hormones. Only ovarian failure or an Hypothalamic failure will be positive for combined estrogen and progesterone challenge test.', 'role': 'assistant'}]