$\underset{¯}{\mathrm{A}}\to \underset{\text{ (Green) }}{2\underset{¯}{\mathrm{B}}}+2{\mathrm{H}}_2\mathrm{O}$

$3\underset{¯}{\mathrm{B}}\stackrel{4\mathrm{HCl}}{\to }\underset{¯}{2}+\underset{(\text{ Purple) }}{{\mathrm{MnO}}_2}+2{\mathrm{H}}_2\mathrm{O}$
$2C\stackrel{H_{2}O,Kl}{\to } 2\underline{A} + 2KOH + \underline{D}$

In the above sequence of reactions, $\underset{¯}{A}$ and $\underset{¯}{D}$ respectively, are

$$\begin{gathered} 2\underset{\left(\mathrm{A}\right)}{\mathrm{M}}\mathrm{n}{\mathrm{O}}_2\stackrel{4\mathrm{KOH} + {\mathrm{O}}_2}{\to } 2\underset{\mathrm{Green} \left(\mathrm{B}\right)}{{\mathrm{K}}_2{\mathrm{MnO}}_4} + 2{\mathrm{H}}_2\mathrm{O} \\ 3{\mathrm{K}}_2{\mathrm{MnO}}_4 \stackrel{4\mathrm{HCl}}{\to } \underset{\mathrm{Purple} \left(\mathrm{C}\right)}{2{\mathrm{KMnO}}_4} + 2{\mathrm{H}}_2\mathrm{O} + {\mathrm{MnO}}_2 + 4\mathrm{KCl} \\ \underset{\left(\mathrm{C}\right)}{2{\mathrm{KMnO}}_4}\stackrel{{\mathrm{H}}_2\mathrm{O},\mathrm{KI}}{\to } \underset{\left(\mathrm{A}\right)}{2{\mathrm{MnO}}_2} + 2\mathrm{KOH} + \underset{\left(\mathrm{D}\right)}{{\mathrm{KIO}}_3} \end{gathered}$$

Therefore, the correct option is C