Which of the following is NOT a form of anticorrosion protection?

Body filler is primarily used to repair and smoothen the surface of a vehicle's bodywork after dents or scratches, rather than to provide protection against corrosion. It fills imperfections but does not contain properties that actively inhibit rust or corrosion formation, making it ineffective as a form of anticorrosion protection.

In contrast, seam sealers are designed to seal joints and seams on a vehicle, preventing moisture and contaminants from entering and causing corrosion. Weld-through primers serve to protect areas of metal that will be welded, minimizing rust in these high-risk areas. Rust converters chemically transform existing rust into a stable compound, thus providing a protective barrier against further corrosion. Each of these options has a specific focus on corrosion prevention, while body filler does not address corrosion directly.