This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 2, Subject name: Forensic Medicine
Bluish green postmoem staining is present in: 
Select and explain. 
A. Hydrogen sulphide, B. Carbon monoxide, C. Cyanide, D. Phosphorus
A: Hydrogen sulphide
Answer: A: Hydrogen sulphide 
Explanation: Normal : Blue purplish Carbon monoxide : Cherry red Cyanide : Bright Red/ Brick red Hypothermia/ Refrigeration : Pink Nitrate/ aniline/ Potassium chlorate : Chocolate Brown Septic aboion : Bronze Hydrogen sulphide : Bluish Green