This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
[{'content': 'All of the following statements about phenytoin are true except: \nSelect and explain. \nA. It follows Saturation kinetics, B. Anti-seizure activity closely resembles plasma concentration, C. Does not depress CNS, D. Cerebellar degeneration occurs on long-term administration', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Phenytoin is not a CNS depressant; some sedation occurs at therapeutic doses, but this does not increase fuher with dose; rather toxic doses produce excitement and muscular rigidity. REF: ESSENTIALS OF MEDICAL PHARMACOLOGY KD TRIPATHI 8TH ED.', 'role': 'assistant'}]