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
Age related dementia has been associated with increased levels of- 
Select and explain. 
A. Homocysteine, B. Cysteine, C. Tourine, D. Methionine
A: Homocysteine
Answer: A: Homocysteine 
Explanation: None