This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Biochemistry
[{'content': 'Anticholinesterase that binds only with the anionic site is \nSelect and explain. \nA. Physostigmine, B. Edrophonium, C. Neostigmine, D. Echothiophate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: .', 'role': 'assistant'}]