This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Injuries by Firearms, Subject name: Forensic Medicine
[{'content': 'Which of the following is not seen in black gun powder of Bullet: \nSelect and explain. \nA. Sulphur, B. Charcoal, C. Potassium, D. Nitrocellulose', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) NitrocelluloseRef: The essentials of FSM by KS Narayan Reddy 31st ed. /197-98Gun powders can be of two types and is made of:Black gun powderSmokeless powderConsists of:* Potassium nitrate 75%* Sulphur 10%* Charcoal 15%Consists of:* Nitrocellulose (single base; gun cotton)* Nitroglycerine + Nitrocellulose* Nitroglycerine + Nitrocellulose + Nitroguanidine (triple base)', 'role': 'assistant'}]