Answer:
C
Explanation:
Nitrogen is fixed in the soil from the atmosphere, in a process called nitrification, by nitrogen-fixing bacteria or on a rare occasion, by lightning strikes. The nitrogen is fixed as, ammonia, nitrites, and nitrates. These nitrogen-based compounds are then taken up by plants and used to make nitrogen-based bio-molecules such as amino acids and nucleic acids. When plants are consumed by primary consumers, these compounds are transferred up in the food chain.
