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': 'Which hormone is required for late-stage development of antral follicles \nSelect and explain. \nA. Androstenedione, B. FSH, C. LH, D. Estradiol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: FSH is required for development of large antral follicles in later stage, although not required for early follicular maturation.', 'role': 'assistant'}]