A 70 year old man presents with h/o prosopagnosia loss of memory, 3rd person hallucination since 1 month.On examination deep Tendon reflexes are increased, minimental examination score is 20/30.What is most likely diagnosis -

• A. Alzheimer's disease
• B. Dissociated Dementia
• C. Schizphrenia
• D. Psychotic disorder