This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetic and genetic disorders, Subject name: Pediatrics
Recent marker for Downs syndrome is 
Select and explain. 
A. HCG, B. Alpha fetoprotein, C. Inhibin, D. Estriol
C: Inhibin
Answer: C: Inhibin 
Explanation: Inhibin A is a protein secreted by the ovary, and is designed to inhibit the production of the hormone FSH by the pituitary gland. The level of inhibin A is increased in the blood of mothers of fetuses with Down syndrome. Reference: GHAI Essential pediatrics, 8th edition