`KMnO_(4)` can be prepared from `K_(2)MnO_(4)` as per the reaction, `3MnO_(4)^(2-)+2H_(2)O hArr 2MnO_(4)^(2-)+MnO_(2)+4OH^(-)`
The reaction can go to completion by removing `OH^(-)` ions by adding.

Options

A. KOH
B. `CO_(2)`
C. `SO_(2)`
D. `KCl`

Answer

B

Explanation

HCl and `SO_(2)` are reducing agents and can reduce `MnO_(4)^(-).CO_(2)` which is neither oxidising and nor reducing will provide only acidic medium. It can shift reaction in forward direction and reaction can go to completion.