Fill up the blanks in the following statements with suitable options.                       

A) Conversion of organic nitrogenous substances present in soil into ammonia is called as ammonification. which is caused by ammonifying bacteria such as (i).

B) Conversion of ammonia present in soil first into nitrites and then into nitrates is called as nitrification, which is done by nitrifying bacteria such as (ii) and (iii) respectively.

C) Conversion of nitrates present in denitrification, which is caused by denitrifying bacteria  such as (iv).