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
You are being asked to give your expert opinion as a toxicologist regarding an effective antidote for belladonna poisoning. Which of the following agents would you suggest? 
Select and explain. 
A. Neostigmine, B. Physostigmine, C. Pilocarpine, D. Methacholine
B: Physostigmine
Answer: B: Physostigmine 
Explanation: None