This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Degenerative Disorders, Subject name: Psychiatry
[{'content': "Drug used in alzheimer's disease are all EXCEPT: \nSelect and explain. \nA. Biperidin, B. Donepezil, C. Rivastigmine, D. Memantine", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) BiperidinRef.: Harrison 19th ed. / 2601-02Alzheimer's disease is most common cause of dementia.Drugs Used in the Treatment of Alzheimer's are:* Acetycholine esterase inhiitors:# Donepezil# Tacrine# Galantamine* Rivastigmine: Carbamate derivative of physostigmine* Memantine: NMDA glutaminergic antagonist* Biperidin is an anti cholinergic drug used to treat parkinsonism.", 'role': 'assistant'}]