Chemistry - Complete d-block Question with Solution | TestHub

The alkaline oxidative fusion is a redox reaction (undergoes both oxidation and reduction simultaneously) in which a compound undergoes fusion with itself only, in the presence of a base or an alkaline solution. 

Electrolysis is a chemical process where an electric current is passed through an electrolyte, causing a non-spontaneous chemical reaction to occur, typically resulting in the decomposition of the electrolyte into its constituent elements or ions.

Alkaline oxidative fusion of ${\mathrm{MnO}}_2$ :
$2{\mathrm{MnO}}_2+4{\mathrm{OH}}^{-}+{\mathrm{O}}_2\to 2{\mathrm{MnO}}_4^{2-}+2{\mathrm{H}}_2\mathrm{O}$

Electrolytic oxidation of ${\mathrm{MnO}}_4^{2-}$ in alkaline medium.
${\mathrm{MnO}}_4^{2-}\to {\mathrm{MnO}}_4^{-}+e^{-}$

Hence, the answer is option B.