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

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

An SCBA provides a positive-pressure supply of breathable air from a cylinder, making it the only device suitable for oxygen-deficient atmospheres. Canister masks and dust filters rely on ambient air, which is insufficient in confined spaces where oxygen levels may be below the required 19.5 percent threshold.