Which two inert gases are commonly used to purge flammable or explosive vapors from a confined space?

The correct choice identifies carbon dioxide and nitrogen as the two inert gases commonly utilized to purge flammable or explosive vapors from a confined space. These gases are classified as inert because they do not readily react with other substances, making them ideal for displacing oxygen and reducing the risk of ignition in environments containing potentially explosive vapors.

Nitrogen, in particular, is widely used for purging due to its abundance and low cost. It is effective in creating an oxygen-free environment, which is essential for safety when working in confined spaces where flammable materials may be present. Carbon dioxide also serves a similar purpose; it can help to lower the concentration of oxygen in the air, further reducing the chances of combustion.

In contrast, the other gases listed in the other options do not serve the same safe, inert purpose. Oxygen is necessary for combustion and is not an inert gas. Argon, while inert, is not as commonly used for this specific application compared to nitrogen and carbon dioxide. Helium and xenon, while also inert, are not practical for purging flammable vapors due to their higher costs and lesser availability. Hydrogen and methane, on the other hand, are flammable gases themselves, which makes them highly inappropriate for this application