This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: PCOD, hirsutism and galactorrhea, Subject name: Gynaecology & Obstetrics
[{'content': 'A 28 years old lady is suspected to have polycystic ovarian disease. Sample for testing LH & FSH are best taken on the following days of menstrual cycle: \nSelect and explain. \nA. 4-Jan, B. 10-Aug, C. 13-15, D. 24-26', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In PCOS, determination of FSH and LH levels may help to confirm the diagnosis of polycystic ovaries.These are assayed on 2nd or 3rd day of the cycle.', 'role': 'assistant'}]