If you are machining work held between lathe centers, and the lathe centers begin to squeal, you should first __________.

Correct Answer: Option B — stop the lathe

Squealing lathe centers indicate a lack of lubrication or excessive heat buildup due to friction, which can ruin the centers and the workpiece. Stopping the lathe immediately is the correct safety and maintenance procedure to prevent permanent damage to the machine's precision components and ensure operator safety.