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
Atropine is derived from which of the following plant? 
Select and explain. 
A. Atropa belladonna, B. Hyoscyamus niger, C. Datura stramonium, D. Argemone mexicana
A: Atropa belladonna
Answer: A: Atropa belladonna 
Explanation: 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.