In the reaction $3Br_2 + 6CO_3^{2-} + 3H_2O \to 5Br^- + BrO_3^- + 6HCO_3^-$,which of the following is true?

Which of the following reactions are disproportionation reactions?
$(A)$ $2 Cu^{+} \rightarrow Cu^{2+} + Cu$
$(B)$ $3 MnO_4^{2-} + 4 H^{+} \rightarrow 2 MnO_4^{-} + MnO_2 + 2 H_2 O$
$(C)$ $2 KMnO_4 \rightarrow K_2 MnO_4 + MnO_2 + O_2$
$(D)$ $2 MnO_4^{-} + 3 Mn^{2+} + 2 H_2 O \rightarrow 5 MnO_2 + 4 H^{+}$
Choose the correct answer from the options given below:

Among $P_4$,$S_8$ and $N_2$,the elements which undergo disproportionation when heated with $NaOH$ solution are:

When white phosphorus reacts with caustic soda,$PH_3$ and $NaH_2PO_2$ are produced. This reaction is an example of what?

Assign $A, B, C, D$ from the given type of reaction.
$Hg_2(NO_3)_2 + 2NH_3(aq) + H_2O \longrightarrow Hg \downarrow + Hg(NH_2)NO_3 \downarrow + NH_4NO_3$
(Note: The reaction represents the disproportionation of mercury$(I)$ nitrate with ammonia.)

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 :