Metabolizing nitrogen in prokaryotes is very important to other organisms since these prokaryotes are able to convert ammonium in the soil to nitrate and, then, the denitrifying bacteria could use the nitrate produced instead of using oxygen in their metabolism in order to release nitrogen molecules. by the denitrification process, thus completing the nitrogen cycle. Without the nitrogen metabolism in prokaryotes, the nitrogen in the atmosphere could not be used or utilized to synthesize essential organic compounds that are needed by other organisms. It is only the prokaryotes that has the ability fixing nitrogen or can do the process of nitrogen fixation.
The correct answer is D. for sure.
Because the soil didn't have the same nutrients it has now due to lack of decomposition of other plants and animals.
Assuming it's only salt water, it should be 85%