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: Psychiatry
Following are predispositions to Alzhiemer's desease except : 
Select and explain. 
A. Down's syndrome, B. Down's syndrome, C. Smoking, D. Low education group
C: Smoking
Answer: C: Smoking 
Explanation: C i.e. Smoking