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': 'FG, FFG, FFFG....used to describe - \nSelect and explain. \nA. Primer, B. Caridge, C. Black gunpowder, D. Base of firearms', 'role': 'user'}, {'content': 'Answer: C \nExplanation: the synopsis of forensic medicine & toxicology ; Dr k.s narayan reddy ; 28th edition ; Pg.no. 125 ; Black powder is designated as FG,FFG,FFFGetc depending on the size of grains . The more number of F the finer are the grains & faster is the burning .', 'role': 'assistant'}]