This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Poisoning, Subject name: Forensic Medicine
[{'content': 'The oral fatal dose of potassium cyanide is \nSelect and explain. \nA. 5-10 mg, B. 1-2 mg, C. 200-300 mg, D. 1-2 gm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Fatal dose: 50 to 60 mg of pure acid 200-300mg of NaCN and KCN Fatal period: HCN 2-10 min NaCN and KCN 30 min Ref: FORENSIC MEDICINE AND TOXICOLOGY Dr PC IGNATIUS THIRD EDITION PAGE 472', 'role': 'assistant'}]