This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 2, Subject name: Forensic Medicine
[{'content': 'One of the following toxalbumin is used as terrorist weapon \nSelect and explain. \nA. Ricin, B. Abrin, C. Croton, D. Chilly', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ricin obtained from Ricinus communis: most poisonous naturally occurring substances known. Ricin is toxic by numerous exposure routes and its use by terrorists might involve poisoning of water or foodstuffs, inoculation ricin-laced projectiles, or aerosolization of liquid ricin or distribution of powder.', 'role': 'assistant'}]