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
Karsakoff's Psychosis is diagnosed by 
Select and explain. 
A. Peripheral neuropathy, B. Visual hallucination, C. Impairment of long term memory, D. Seizures
C: Impairment of long term memory
Answer: C: Impairment of long term memory 
Explanation: C i.e. Impairment of long term memory