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
Biological amnesia is - 
Select and explain. 
A. Lack of interest, B. Presenile dementia, C. Opioid addiction, D. Hypothyroidism
B: Presenile dementia
Answer: B: Presenile dementia 
Explanation: Biological amnesia:- Head injury (concussion/brain bruises), drugs (Marijuana, alcohol), brain disease (Korsokoff syndrome, Brain tumors, multiple sclerosis, presenile dementia), temporary disturbances in brain blood supply, and transient global amnesia.
Psychological amnesia :- Childhood amnesia, dream amnesia, defensive amnesia