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': 'In case of burning fire in a closed room, death occurs due to: \nSelect and explain. \nA. CO2 poisoning, B. CO poisoning, C. Cardiac fauilre, D. Respiratory failure', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) CO poisoningRef: The essentials of FSM by KS Narayan Reddy 31st ed./582', 'role': 'assistant'}]