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': "Reversible cause of dementia \nSelect and explain. \nA. Hypothyroidism, B. Alzheimer's disease, C. None, D. Vitamin A deficieny", 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e (Hypothyroidism)', 'role': 'assistant'}]