This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Forensic Toxicology - Concepts, Statutes, Evidence, and Techniques, Subject name: Forensic Medicine
[{'content': 'The cause of death could be: \nSelect and explain. \nA. Clostridium, B. CO poisoning, C. Opium poisoning, D. H2S poisoning', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (B). CO poisoningThe picture shows cherry-red postmortem staining which is indicative of carbonmonoxide poisoning.The red lividity is usually associated with a COHb level >30%Clostridium: Bronze colourCO poisoning: cherry redOpium poisoning: blackH2 S poisoning: bluish green', 'role': 'assistant'}]