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': 'A pinch of which of the following poisons can kill as many as five persons : \nSelect and explain. \nA. Arsenic trioxide, B. Copper sulphate, C. Lead sulphate, D. Arsenic disulphate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Arsenic trioxide', 'role': 'assistant'}]