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
Which hormone is required for late-stage development of antral follicles 
Select and explain. 
A. Androstenedione, B. FSH, C. LH, D. Estradiol
B: FSH
Answer: B: FSH 
Explanation: FSH is required for development of large antral follicles in later stage, although not required for early follicular maturation.