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
[{'content': "Treatable causes of dementia are : \nSelect and explain. \nA. Alzheimer's ds., B. Hypothyroidism, C. Multi-infarct dementia, D. All", 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Hypothyroidism', 'role': 'assistant'}]