In Order for Most Organisms to Use the Nitrogen in the Atmosphere

In order for most organisms to use the nitrogen in the atmosphere, dinitrogen gas must be

A) taken in by green plants and transformed into nitrogen-rich protein.
B) inhaled by herbivores and transformed into ammonia, which can be dissolved in their blood.
C) taken up by certain bacteria that can change it into ammonium, a form that is available for plants.
D) dissolved in an aqueous solution to form nitrate.