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': 'Fish tailing of margins in stab wound is seen with? \nSelect and explain. \nA. Single edged knife, B. Double edged knife, C. Bayonet, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Fish tailing of margins in stab wound is seen with single edged knife. A knife blade with a double edge will normally produce a symmetrical elliptical wound with both ends pointed; a knife with a single-edged blade may show relative blunting ("fish-tailing") of one end of the entry slit. However, a single edged blade can produce a wound with two pointed ends, mimicking an injury from a double edged blade. A bayonet, which has a ridge along the back of the blade with a groove along each side, may produce a slit like an elongated letter "T".', 'role': 'assistant'}]