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: Pharmacology
[{'content': "Which of the following drug is not used for the treatment of Alzheimer's disease: \nSelect and explain. \nA. Tacrine., B. Physostigmine., C. Rivastigmine., D. Donepezil.", 'role': 'user'}, {'content': "Answer: B \nExplanation: Alzhiemer's\n\nTacrine\nDonepezil\nRivastigmine\nGallantamine", 'role': 'assistant'}]