Answer:
C. lack the enzymes to reduce N2 and NO3- to NH4+
Step-by-step explanation:
Nitrogen fixation is a process by which atmospheric nitrogen (N2) is converted into ammonia (NH3) so that can be used in metabolic pathways (e.g. biosynthesis of macromolecules). Nitrogen fixation is performed by Archea and bacteria such as Azotobacter (usually in symbiosis with Leguminosa plants).
Nitrogen assimilation is a process in which organic compounds are made from inorganic nitrogen.