Which of the following reagent shows visible change when treated with sulphite ion?

Based on the green color that results from the treatment of sulphide ions in ammoniacal solution with iron(III) and an excess of nitrilotriacetic acid, an absorptiometric technique for sulphide ions is presented.

In an acidic medium the sulphite ions get converted to sulphate ions. For every 2 moles of potassium permanganate, 5 moles of sulphite are produced or converted to sulphate ions.

So the correct process are,

${\mathrm{KHCO}}_3\text{ (solution) }\stackrel{{\mathrm{AgNO}}_3}{⟶}\text{ Solution }\stackrel{\text{ boil }}{⟶}\text{ White ppt. }$

${\mathrm{KHCO}}_3\text{ (solution) }\stackrel{{\mathrm{BaCl}}_2}{\to }\text{ Solution }\stackrel{\text{ boil }}{⟶}\text{ White ppt. }$

${\mathrm{KHCO}}_3\text{ (solution) }\stackrel{{\mathrm{AgNO}}_3}{\to }\text{ Solution }\frac{{\mathrm{H}}_8{\mathrm{Cl}}_2}{\text{ Boil }}\text{ Reddish brown ppt. }$