The gas used to extinguish fire is A. Neon B. Nitrogen C. Carbon dioxide D. Carbon monoxide

The correct answer is C. Carbon dioxide.

Carbon dioxide is a gas that is used to extinguish fires because it does not support combustion. This means that it will not allow the fire to continue to burn. Carbon dioxide is also non-toxic and non-flammable, making it a safe option for fire suppression.

Neon, nitrogen, and carbon monoxide are all gases that are not used to extinguish fires. Neon is a noble gas that does not react with other elements. Nitrogen is an inert gas that does not support combustion. Carbon monoxide is a toxic gas that can be fatal if inhaled.

Here is a more detailed explanation of each option:

• Neon is a noble gas that does not react with other elements. This means that it will not interfere with the fire and will not help to extinguish it.
• Nitrogen is an inert gas that does not support combustion. This means that it will not allow the fire to continue to burn. However, nitrogen is not as effective at extinguishing fires as carbon dioxide.
• Carbon monoxide is a toxic gas that can be fatal if inhaled. It is not used to extinguish fires because it is dangerous to humans.

I hope this helps!