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: Physiology
[{'content': 'Lesions within the basal ganglia produce the following signs except: \nSelect and explain. \nA. Hypotonia, B. Tremor, C. Hemiballismus, D. Athetosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]