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: Forensic Medicine
[{'content': 'Atropine is derived from which of the following plant? \nSelect and explain. \nA. Atropa belladonna, B. Hyoscyamus niger, C. Datura stramonium, D. Argemone mexicana', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Plants and mushrooms containing anticholinergic alkaloids include Jimsonweed (Datura stramonium) Deadly nightshade (Atropa belladonna) Fly agaric (Amanita muscaria) The root of Atropa belladonna contains 82-97% of hyoscyamine, 3-15% atropine, and up to 2.5% scopolamine. Anticholinergic agents competitively antagonize the effects of acetylcholine at peripheral muscarinic and central receptors. Ref: Manning B.H. (2012). Chapter 13. Anticholinergics. In K.R. Olson (Ed), Poisoning & Drug Overdose, 6e.', 'role': 'assistant'}]