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
Biochemical etiology of Alzheimer's disease relates it to : 
Select and explain. 
A. Acetylcholine, B. GABA, C. Serotinin, D. Dopamine
A: Acetylcholine
Answer: A: Acetylcholine 
Explanation: A i.e. Acetyl choline