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 color in postmoem staining is a feature of poisoning with: WB 08; NEET 13 \nSelect and explain. \nA. Nitrites, B. Aniline, C. Phosphorus, D. CO', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. CO', 'role': 'assistant'}]