This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mechanical injuries, Subject name: Forensic Medicine
[{'content': 'Double based smokeless gun powder consist of - \nSelect and explain. \nA. Nitrocellulose plus nitroglycerine, B. Nitrocellulose plus sulphur, C. Potassium nitrate plus nitroglycerine, D. Potassium nitrate plus charcoal', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The synopsis of forensic medicine & toxicology ; Dr k.s narayan reddy ; 28th edition ; Pg.no. 125 Nitrocellulose -single base Nitrocellulose & nitroglycerin - double base Nitrocellulose, nitroglycerin, nitroguanidine - triple base', 'role': 'assistant'}]