Which of the following statements is true concerning carbon dioxide when used as a fire extinguishing agent?

Correct Answer: Option C — Its smothering effect is excellent for class B fires.

Carbon dioxide is an inert gas that displaces oxygen, effectively smothering Class B (flammable liquid) fires. It is non-conductive and leaves no residue, making it ideal for machinery spaces. However, it lacks the cooling capacity of water, so it must be used with caution to prevent re-ignition.