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': 'Post menopausal estrogen production is due to : \nSelect and explain. \nA. Peripheral aromatization of androstenedione, B. Adrenal - direct production, C. Ovarian tumor, D. Ovary testosterone secretion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In menopause estrogen levels decrease by 66%.\nMain source of estrogen production postmenopausaly is by peripheral aromatization of androstenedione.\nMain estrogen after menopause - oestrone.', 'role': 'assistant'}]