All the following conditions must be present for a fire to start except

The answer is A. Nitrogen to support fire.

You can refer to the FIRE TRIANGLE or COMBUSTION TRIANGLE, for this. The triangle illustrates the 3 elements needed to ignite a fire. The three elements are oxygen, heat, and fuel. If all three of these elements are put together in the right mixture and amount, a fire will occur. 

All the following conditions must be present for a fire to start except Nitrogen.

Explanation:

Four components are required to form a fire: fuel, oxygen, heat, and a chemical change. Fuel is any combustible, solid, liquid or gas. Most solids or liquids become a vapor or gas before they burn. On the other hand, nitrogen prevents the fire from getting enough oxygen to continue burning.

"observation" would be the correct answer

Answer(a); implementation of drug formulary checks;