Which of the devices listed would be safe to use in a compartment with insufficient oxygen?

Correct Answer: Option B — Self-contained breathing apparatus.

Only a self-contained breathing apparatus (SCBA) provides an independent supply of breathable air. Masks, canisters, and wet handkerchiefs rely on filtering ambient air, which is ineffective in oxygen-deficient atmospheres. In such environments, the lack of oxygen makes any filtration device useless, as they do not provide the necessary life-sustaining oxygen.