Answer:
Im pretty sure its C
Step-by-step explanation:
Denitrifying bacteria release nitrogen by breaking down ammonia and nitrates. This process called denitrification. Nitrogen from denitrification is released into the atmosphere. The rate at which nitrogen is removed from the atmosphere by fixation is balanced by the rate at which nitrogen is returned to the atmosphere by denitrification. This balance may be upset by the use of artificial fertilizers. More nitrogen may be fixed than can be returned by denitrification.