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
Double based smokeless gun powder consists of 
Select and explain. 
A. Nitrocellulose plus nitroglycerine, B. Nitrocellulose plus sulphur, C. Potassium nitrate plus nitroglycerine, D. Potassium nitrate plus charcoal
A: Nitrocellulose plus nitroglycerine
Answer: A: Nitrocellulose plus nitroglycerine 
Explanation: Ans. a. Nitrocellulose plus Nitroglycerine Gun-Powder Smokeless Powder Nitrocellulose (gun cotton)deg Nitrocellulose and Nitroglycerine (double base)deg Smoke producing powders Black Powder: It is described in FG, FFG, FFFG and so on depending on the size of the grains. The finer and faster burning grains have more numbers of Fs. It contains PCSdeg Potassium nitrate (75%)deg Charcoal (15%)deg Sulphur (10deg/0)deg Pyrodex: PCS Potassium perchlorate Sodium benzoate, Dicyandiamide, Dextrin wax Semismokeless powder 80% of black and 20% of smokeless powder