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': 'Hemiballismus is due to lesion in? \nSelect and explain. \nA. Ipsilateral Caudate nucleus, B. Contralateral sub-thalamic lesion, C. Contralateral Putamen, D. Ipsilateral sub-thalamic lesion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) Contralateral subthalamic lesionRef: Harrison 19th ed. / 2623LesionManifestation* Caudate nucleusContralateral chorea* Globus pallidusContralateral atheotosis* Sub-thalamic nucleusContralateral hemiballismus* CerebellumIpsilateral intentional tremors* Internal capsuleContra-lateral hemiplegia with hemi- anesthesia* Ventral ponsLocked in syndrome', 'role': 'assistant'}]