Right choice is (a) Phosphate into TSS
Explanation: The phosphate removal from wastewater involves the unification of Phosphate into TSS into the waste water, i.e. phosphate to merge with the total suspended solids and then it’s removal from the solids, removal of nitrogen gas from waste water i.e. the final step is called as denitrification, ammonification is conversion into ammonia, desalination is a procedure by which salt is removed from water bodies, this step is not followed for nitrogen removal.