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': 'Which of the following poison causes cherry-red -color postmoem staining? \nSelect and explain. \nA. Carbon monoxide, B. Aniline, C. Phosphorus, D. Nitrites', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A cherry-red colouration of the skin, mucous membranes, conjunctiva, nail beds, areas of hypostasis, blood, tissues and internal organs is seen in carbon monoxide (CO) poisoning. It is associated with 30-40% COHb. Ref: The Essentials of Forensic Medicine and Toxicology by Narayan Reddy, 27th edition, Page 555.', 'role': 'assistant'}]