This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of menstruation, Subject name: Gynaecology & Obstetrics
[{'content': 'Peak level of LH required for ovulation: \nSelect and explain. \nA. 15 ng/ml, B. 50ng/ml, C. 30ng/ml, D. 75ng/ml', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Peak level of LH required for ovulation is 75 ng/ml It lasts for 24 hrs Ref: Shaw Gynecology 17 e pg 40.', 'role': 'assistant'}]