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
Deep Brain Stimulation of which part of brain has been shown to reduce frequency of symptoms in Parkinsonism- 
Select and explain. 
A. Striatus, B. Globus Pallidus Externus, C. Subthalamic nucleus, D. Putamen
C: Subthalamic nucleus
Answer: C: Subthalamic nucleus 
Explanation: None