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
[{'content': 'FG, FFG, FFFG is used to indicate: PGI 08, 11 \nSelect and explain. \nA. Caridge, B. Black powder size, C. Base of gun, D. Wadding of caridge', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Black powder size', 'role': 'assistant'}]