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': 'Cherry red colour of blood is seen in poisoning with- \nSelect and explain. \nA. Nitrate, B. Cyanide, C. Lead, D. Sulphite', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]