Which of the following gases supports burning?

Oxygen

The correct answer is option 3. Oxygen.

The gas that supports burning is Oxygen. Oxygen is a supporter of combustion or burning. It is essential for most combustion reactions to occur. When a material burns, it reacts with oxygen in the air, producing heat and often light.

Nitrogen and carbon dioxide, on the other hand, do not support combustion. Nitrogen is generally inert in combustion processes, and carbon dioxide, while produced during combustion, does not itself support the burning of materials.