The correct answer is option D, that is, look for soil bacteria, which transforms nitrates into nitrogen gas.
A microbial mediated procedure where nitrate is reduced and eventually generating molecular nitrogen via an array of intermediate gaseous nitrogen gaseous outcomes is known as denitrification.
It is generally the withdrawal or the loss of nitrogen or nitrogen components, mainly the reduction of nitrites or nitrates by the bacteria in the soil, which usually leads to the escape of nitrogen into the atmosphere.
