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
Follistatin 
Select and explain. 
A. Decreased gonadotrope function, B. Increases gonadotrope function, C. Prevents interaction of activin with receptor, D. Stimulates FSH β gene expression
C: Prevents interaction of activin with receptor
Answer: C: Prevents interaction of activin with receptor 
Explanation: Follistatin is gonadal peptide, that suppresses FSH β gene expression thereby preventing interaction of activin with its receptor.