This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
The most common cause of organic amnestic syndrome is 
Select and explain. 
A. Alzheimer's disease, B. Concussion, C. Hypoxia, D. Vitamin deficiency
D: Vitamin deficiency
Answer: D: Vitamin deficiency 
Explanation: organic amnesia and the amnestic syndrome. .The amnestic syndrome is characterized by disorientation paicularly in time, impairment of immediate recall, loss of recent memory, retroactive loss of remote memory of varying extent and a tendency to confabulation. Ref Harrison20th edition pg 2776