In the following Latimer diagram, the species that undergoes disproportionation reaction is
\[
\text{MnO}_4^- \xrightarrow{+0.56} \text{MnO}_4^{2-} \xrightarrow{+0.27} \text{MnO}_3^- \xrightarrow{+0.93} \text{MnO}_2 \xrightarrow{+0.15} \text{Mn}_2\text{O}_3 \xrightarrow{-0.25} \text{Mn(OH)}_2 \xrightarrow{-1.56} \text{Mn}
\]