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': 'Vascular dementia is characterised by all except \nSelect and explain. \nA. Visual hallucination, B. Memory deficit, C. Emotional liability, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dementia is a chronic organic mental disorder, characterized by the following main clinical features: 1. Impairment of intellectual functions, 2. Impairment of memory (predominantly of recent memory, especially in early stages), 3. Deterioration of personality with lack of personal care. Reference: A sho textbook of Psychiatry by Niraj Ahuja, page no.22.', 'role': 'assistant'}]