This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Specific Cytogenetic Disorders, Subject name: Pathology
All of the following are true statements about Down syndrome, except: 
Select and explain. 
A. Most common inheritable cause of mental retardation, B. In quadruple test, Inhibin-A level is reduced, C. Most common cause is meiotic non-disjunction, D. In triple test (AFP |, estriol |, hcG |)
B: In quadruple test, Inhibin-A level is reduced
Answer: B: In quadruple test, Inhibin-A level is reduced 
Explanation: ANTENATAL SCREENING FOR DOWN SYNDROME: TRIPLE TEST b-hCG || Maternal Serum Alpha fetoprotein (MSAFP) || Unconjugated Estriol (uE3) || QUADRUPLE TEST b-hCG || Maternal Serum Alpha fetoprotein (MSAFP) || Unconjugated Estriol (uE3) || Dimeric Inhibin-A || OTHER OPTIONS Down syndrome is most common inheritable cause of mental retardation- true Most common cause of Down syndrome is meiotic non-disjunction, followed by Robesonian translocation- true