What statement most directly demonstrates a way that the geosphere is involved in the nitrogen cyclea. fossil fuels form when decaying organisms are buried underground for long periods b. bacteria that convert ammonia into nitrites and nitrates are found in the soil c. some plants absorb nitrogen from the air and use it to form proteins d. animals break down proteins and other nitrogen-containing compounds in two waste products

Bacteria living in the soil in root nodules of various plants are directly involved in the nitrogen cycle. The nitrifying bacteria "Nitrobacters" and "Nitrosomonas" can fix atmospheric nitrogen and can convert it into nitrates and nitrites. As plants can not directly fix that atmospheric nitrogen so these Nitrobacters and Nitrosomonas who lives in symbiotic relation in their root nodules do this nitrogen fixation for them. So these bacteria provide them nitrates and nitrates that plants can directly uptake and can use in their essential metabolic cycles. In this way, Geosphere plays a critical role in nitrogen fixation.

B. bacteria that convert ammonia into nitrites and nitrates are found in the soil  

This statement best demonstrates a way that the geo-sphere is involved in the nitrogen cycle.

A nitrogen cycle is defined as the movement of nitrogen between the atmosphere, biosphere, and geo-sphere in different forms. Ammonia is converted to nitrates by nitrifying bacteria in the soil. Then the plants absorb these nitrates from the soil and use these to build up proteins.

answer; /// i believe that the correct answer is (50%);