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': 'Deep Brain Stimulation of which part of brain has been shown to reduce frequency of symptoms in Parkinsonism- \nSelect and explain. \nA. Striatus, B. Globus Pallidus Externus, C. Subthalamic nucleus, D. Putamen', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]