Which of the following behaves as both an oxidising and a reducing agent?

Identify the pair of reactions undergoing disproportionation from the following.

The species that undergo disproportionation in alkaline medium are
$(a) \, Cl_2 \, \, \, (b) \, MnO_4^{2-} \, \, \, (c) \, NO_2 \, \, \, (d) \, ClO_4^{-} $

White $P_4$ reacts with caustic soda,the products are $PH_3$ and $NaH_2PO_2$. This reaction is an example of

Given below are two statements :
Statement $I$: $S_8$ solid undergoes disproportionation reaction under alkaline conditions to form $S^{2-}$ and $S_2O_3^{2-}$.
Statement $II$: $ClO_4^{-}$ can undergo disproportionation reaction under acidic condition.
In the light of the above statements,choose the most appropriate answer from the options given below :

Identify the correct statement for the following reaction: $3 Br_2 + 6 CO_3^{2-} + 3 H_2O \rightarrow 5 Br^{-} + BrO_3^- + 6 HCO_3^-$