Concept:A loosely fitted needle can move or fall out during sewing, causing it to break.Explanation:Tighten the needle screw so the needle is held firmly in place.This prevents the needle from moving, hitting the throat plate, or breaking while stitching.Pulling the fabric, loosening the presser foot, or using thick seams are not correct ways to prevent needle breakage.Answer:B. tighten needle screw.