The correct option is C deamination
During digestion, proteins are broken down into amino acids and nucleic acids are converted into nitrogenous bases. Next step of protein and nucleic acid digestion is deamination. Deamination is removal of amino groups.
Ammonification is one of the steps in the nitrogen cycle. It is the decomposition of organic nitrogen into ammonia. The process is carried out by ammonifying bacteria.
Denitrification is another step of the nitrogen cycle in which nitrates are converted back to atmospheric nitrogen.
Nitrification is the process of conversion of ammonia into nitrates. This is another important step in the nitrogen cycle.