Bacteria (Pseudomonas and Clostridium) use nitrates in the soil to carry out respiration and consequently produce nitrogen gas. This process is called ___ .

The correct option is B

Denitrification

Denitrification is the reduction of nitrates back into the largely inert nitrogen gas $\left(N_2\right)$. Biological denitrification is an anaerobic respiration reaction in which nitrate $\left(N{O}_3\right)$ is reduced. This process is carried out by facultative heterotrophic bacteria (Pseudomonas and Clostridium).