Where must inspection stickers and decals be kept to avoid loss or damage?

Answer: B — Under lock

Inspection stickers and decals must be kept under lock to ensure their security and prevent unauthorized access or damage. This practice is essential because these stickers and decals serve as official proof of vehicle inspection compliance, and if they were to fall into the wrong hands or get damaged, it could lead to fraudulent use or validation of non-compliance. Storing them in a locked location minimizes the risks associated with theft and mishandling, maintaining the integrity and accountability of the inspection process. The other options, while they may suggest methods of storage, do not provide the same level of security that a locked environment offers. A filing cabinet may be easily accessed, a bulletin board lacks security features, and a safe deposit box, while secure, is often impractical for items that need to be quickly available for inspection procedures.