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: Medicine
[{'content': "Dinesh, a 56-yr-aged man presents with complaints of the slowness of movements, postural instability, tremors, rigidity and memory loss. Most likely diagnosis is - \nSelect and explain. \nA. Multi infarct dementia, B. Alzheimer's disease, C. Parkinsonism, D. None of the above", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]