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
Blue hypostasis is seen in poisoning due to - 
Select and explain. 
A. H2S, B. Phosphorus, C. CO, D. Organophosphorus compounds
A: H2S
Answer: A: H2S 
Explanation: None