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': "Which of the following is a 'nootropic' drug? \nSelect and explain. \nA. Rivastigmine, B. Tacrine, C. Amantadine, D. Piracetam", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Nootropic drugs are newer class of drugs to improvr the cognitive capacity in alzheimers patient. aThey include piracetam and aneracitam REFR: ESSENTIALS OF MEDICAL PHARMACOLOGY KD TRIPATHI 8TH ED.', 'role': 'assistant'}]