This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
[{'content': "All of the following casues subcoical dementia except - \nSelect and explain. \nA. Alzhimer's disease, B. Parkinsonism, C. HIV encephalopathy, D. Progressive supra nuclear palsy", 'role': 'user'}, {'content': "Answer: A \nExplanation: The pa of brain affected in Alzheimer's disease is cerebral coex and hippocampus. In parkinsonism, basal ganglia, coex and even the brainstem(subcoex) is affected. In progressive supranuclear palsy and HIV encephalopathy there is subcoical dementia. Reference Harrison20th edition pg 2456", 'role': 'assistant'}]