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': 'Death due to which poison causes postmoem staining of cherry-red -color: \nSelect and explain. \nA. Carbon monoxide, B. Aniline, C. Phosphorus, D. Nitrites', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Carbon monoxide', 'role': 'assistant'}]