Which of the following reactions are disproportionation reaction? 2 Cu ^ + Cu ^ 2+ + Cu ^…

Which of the following reactions are disproportionation reaction?

1. \(2 \mathrm{Cu}^{+} \longrightarrow \mathrm{Cu}^{2+}+\mathrm{Cu}^{8}\)
2. \(3 \mathrm{MnO}_{4}^{2-}+4 \mathrm{H}^{+} \longrightarrow 2 \mathrm{MnO}_{4}^{-}+\mathrm{MnO}_{2}+2 \mathrm{H}_{2} \mathrm{O}\)
3. \(2 \mathrm{KMnO}_{4} \xrightarrow{\Delta} \mathrm{~K}_{2} \mathrm{MnO}_{4}+\mathrm{MnO}_{2}+\mathrm{O}_{2}\)
4. \(2 \mathrm{MnO}_{4}^{-}+3 \mathrm{Mn}^{2+}+2 \mathrm{H}_{2} \mathrm{O} \longrightarrow 5 \mathrm{MnO}_{2}+4 \mathrm{H}^{\oplus}\)

Select the correct option from the following