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
Which one of the following is not a prion associated disease : 
Select and explain. 
A. Scrapie, B. Kuru, C. Creutzfeldt-Jakob disease, D. Alzheimer's disease
D: Alzheimer's disease
Answer: D: Alzheimer's disease 
Explanation: Answer is D (Alzheimer's disease): Alzheimer's disease is the most common cause of dementia in the Western World. It is not classified as a Prion disease.