Which gases are often considered as part of safe working environments due to their non-combustible nature?

The correct choice indicates that inert gases are often considered as part of safe working environments due to their non-combustible nature. Inert gases, such as nitrogen, argon, and helium, do not readily react with other substances, which means they do not support combustion or contribute to fire hazards. This property makes them valuable in various applications, particularly in environments where flammability is a concern.

In settings like industrial processes, laboratories, and confined spaces, the use of inert gases can help create a safe atmosphere by displacing oxygen and preventing the ignition of flammable materials. Their ability to maintain a non-reactive environment aids in protecting workers and minimizing risks associated with fires and explosions.

Other gases listed, such as oxygen and hydrogen, are reactive and can enhance combustion or create flammable conditions. Carbon dioxide, while non-combustible, is not inert in the same sense as inert gases since it can play a role in other chemical reactions and may not provide the same safety assurance in all scenarios.