Correct Option: C

Nitrogen fixation is a process by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3). Atmospheric nitrogen or molecular nitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds. It is essential for all forms of life because nitrogen is required to biosynthesize basic building blocks of plants, animals and other life forms, e.g., nucleotides for DNA and RNA and amino acids for proteins.