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: Medicine
Memory impairment is most likely to occur in - 
Select and explain. 
A. Downs Syndrome, B. Alkaptonuria, C. Attention deficit disorder, D. Conduct disorder
A: Downs Syndrome
Answer: A: Downs Syndrome 
Explanation: None