Which of the following is an example of Disproportionation of an oxidation state, in which a single substance is simultaneously reduced and oxidized to form two different products one with a higher oxidation state and one with a lower oxidation state?

Question

$(1)\; 2Mn^{3+} (\text{aq}) + 2H_2O (\text{l}) \rightarrow MnO_2(\text{s}) + Mn^{2+}(\text{aq})$

$(2) \;3MnO_4^{-2} + 4H^{+} \rightarrow 2MnO_4^{-} + MnO_2 + 2H_2O$

$(3) \;3CrO_4^{3-} + 8H^{+} \rightarrow 2CrO_4^{2-} + Cr^{3+} + 4H_2O$

$\begin {array} {1 1} Only\;(1)\;and \;(2) \\Only\;(2)\;and \;(3) \\ Only\;(1)\;and \;(3)\\ (1),(2),and \;(3) \end {array}$