When an aqueous solution of \(\mathrm{CuCl}_2\) is electrolysed using Pt inert electrodes, the reaction at cathode and anode respectively are

1. A \(4 \mathrm{H}_2 \mathrm{O}(f) \stackrel{+4 \mathrm{a}^{-}}{\longrightarrow} 2 \mathrm{H}_2(g)+4 \mathrm{OH}_2(\mathrm{aq})\);
   \[
   2 \mathrm{H}_2 \mathrm{O}(l) \stackrel{-4 \mathrm{a}^{-}}{\longrightarrow} \mathrm{O}_2(g)+4 \mathrm{H}^{+}(\mathrm{aq})
   \]
2. B \(2 \mathrm{Cu}^{2 *}(\mathrm{aq}) \stackrel{+\mathrm{se}^{-}}{\longrightarrow} 2 \mathrm{Cu}(\mathrm{s})\);
   \[
   2 \mathrm{H}_2 \mathrm{O}(l) \stackrel{-4 \mathrm{~s}^{-}}{\longrightarrow} \mathrm{O}_2(g)+4 \mathrm{H}^*(a q)
   \]
3. C \(\mathrm{Cu}^{2 *}(\mathrm{aq}) \stackrel{+2 \mathrm{a}^{-}}{\longrightarrow}, \mathrm{Cu}(\mathrm{s}) ; 2 \mathrm{Cl}^{-}(\mathrm{aq}) \stackrel{-2 \mathrm{a}^{-}}{\longrightarrow} \mathrm{Cl}_2(\mathrm{~g})\)
4. D \(2 \mathrm{H}_2 \mathrm{O}(f) \stackrel{+2 \mathrm{a}^{-}}{\longrightarrow} \mathrm{H}_2(g)+2 \overline{\mathrm{O}} \mathrm{H}(\mathrm{aq})\);
   \[
   2 \mathrm{Cl}^{-}(a q) \stackrel{-2 \mathrm{an}^{-}}{\longrightarrow} \mathrm{Cl}_2(g)
   \]