A disproportionation reaction is a reaction in which the same element is simultaneously oxidized and reduced. In this type of reaction, a single substance gives two products, one is oxidized while the other is reduced.
S1:S8+12OH⊝→4S2−+2S2O32−+6H2O
S2:ClO4⊝ cannot undergo disproportionation reaction as chlorine is present in its highest oxidation state.
Hence, statement I is correct and II is incorrect.