This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Organic mental disorders, Subject name: Psychiatry
[{'content': "Most common cause dementia in an adult is \nSelect and explain. \nA. Alzheimer's, B. Multi-infarct, C. Pick disease, D. Metabolic cause", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dementia is a chronic organic mental disorder characterised by impairment of intellectual function, impairment of memory, deterioration of personality with lack of personal care Alzheimer&;s is the commonest cause of dementia seen in about 70% of all cases of dementia in USA. It is more commonly seen in women (Ref: a sho textbook of psychiatry, Niraj Ahuja,7th edition, pg no23)', 'role': 'assistant'}]