Final answer:
When using a prybar to separate wood nailed together and to pull nails, one should wear safety glasses to protect their eyes.
Gripping the center of a nail with pliers helps prevent bending by stabilizing the nail as it is hammered into hard materials.
The correct answer is: a) Safety glasses.
Step-by-step explanation:
Safety glasses will protect your eyes from flying debris, such as small wood chips or pieces of the nail that might break off when prying or hammering.
While gloves, hard hats, and earplugs are important in their respective scenarios, safety glasses are the most relevant form of protection for this specific task.
When using a prybar to separate wood that is nailed together and to pull nails, it is important to ensure personal safety by wearing the correct protective gear.
Regarding the old carpenter's trick, gripping the center of the nail with pliers helps to prevent bending when hammering into hard materials because it stabilizes the nail, providing support and reducing the tendency of the nail to flex under the force of the hammer.
Think of it as adding a temporary 'spine' to the nail that helps it stay straight until it is hammered far enough into the material that it can stand on its own.