The main difference between a common lathe dog and a safety lathe dog is that the latter __________.

Correct Answer: Option B — has a headless set screw

Safety lathe dogs are designed to prevent entanglement hazards for the operator. By utilizing a headless set screw that sits flush with the body of the dog, the device eliminates protruding parts that could catch on clothing or hands during high-speed rotation of the workpiece on the lathe.