This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ballistics, Subject name: Forensic Medicine
Smokeless Gun powder contains 
Select and explain. 
A. Nitrocellulose, B. Charcoal, C. Potassium, D. Sulphur
A: Nitrocellulose
Answer: A: Nitrocellulose 
Explanation: SMOKELESS gun powder: Single base: Nitrocellulose Double base: Nitrocellulose + Nitro-glycerine Triple base: Nitrocellulose + Nitroglycerine + Nitroguanidine