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
Inhibin is secreted by : 
Select and explain. 
A. Graffian follicle, B. Corpus luteum, C. Endometrium, D. Placenta
A: Graffian follicle
Answer: A: Graffian follicle 
Explanation: Graffian follicle