d and f Block Elements Part 2

Disproportionation reactions are redox reaction in which a compound undergoes oxidation as well as reduction. The element of reacting species is in an intermediate oxidation state and simultaneously gets oxidised and reduced.
3

+3

Cl

O2−→

−1

Cl−

+2

+5

Cl

O3−

0

Cl2

‌+OH−→

−1

Cl−

+

+5

ClO3−

+H2O
2Mn3++2H2O→Mn2++

+4

MnO2

+4H+
But MnO4− does not get disproportonated.
Hence, option (c) is the correct answer.