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
[{'content': 'All of the following are true statements about Down syndrome, except: \nSelect and explain. \nA. 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 |)', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 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', 'role': 'assistant'}]