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: Gynaecology & Obstetrics
[{'content': 'In a case of secondary amenorrhea who fails to get withdrawl bleeding after taking E and P, the fault lies at the level of: \nSelect and explain. \nA. Pituitary, B. Hypothalamus, C. Ovary, D. Endometrium', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Estrogen- pro gesterone challenge test\nProcedure: Ethinyl estradiol (.02 mg) or conjugated equine estrogen (1.25 mg) is given daily for 25 days. MDPA 10 mg daily is added from day 15 to 25 (Alternatively estrogen is given for 21 days and progesterone is added in last 5 days).\n↓ The test creates a condition similar to normal menstrual cycle', 'role': 'assistant'}]