Which statement BEST describes how greenhouse gases act as natural insulators in the Earth's system?

A) The gases absorb and emit a part of the heat reflected by Earth’s surface.
B) The gases receive the Sun’s heat directly and deflect a part of it toward Earth’s surface.
C) The gases are formed by the burning of fossil fuels, as a result of which they are very hot.
D) The gases react with each other in the presence of sunlight and release energy in the form of heat.

A. The gases absorb and emit a part of the heat reflected by the Earth's surface

Explanation:

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.