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': 'Blue hypostasis is seen in poisoning due to - \nSelect and explain. \nA. H2S, B. Phosphorus, C. CO, D. Organophosphorus compounds', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]