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
Black gunpowder contains all of the following, except: PGI 06; Punjab 09 
Select and explain. 
A. Potassium nitrate, B. Lead peroxide, C. Charcoal, D. Sulfur
B: Lead peroxide
Answer: B: Lead peroxide 
Explanation: Ans. Lead peroxide