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
A dead body is having cadaveric lividity of bluish green colour. The most likely cause of death is by poisoning due to 
Select and explain. 
A. Hydrocyanic acid, B. Hydrogen sulphide, C. Oleander, D. Sodium nitrite
B: Hydrogen sulphide
Answer: B: Hydrogen sulphide 
Explanation: B i.e. Hydrogen sulphide