In which of the following reactions, hydrogen peroxide acts as an oxidizing agent?

$\mathrm{HOCl} + {\mathrm{H}}_2{\mathrm{O}}_2\to {\mathrm{H}}_3{\mathrm{O}}^{+}+{\mathrm{Cl}}^{–}+{\mathrm{O}}_2$

$2{\mathrm{MnO}}_4^{-}+ 3{\mathrm{H}}_2{\mathrm{O}}_2\to 2{\mathrm{MnO}}_2 + 3{\mathrm{O}}_2+ 2{\mathrm{H}}_2\mathrm{O} + 2{\mathrm{OH}}^{–}$

${\mathrm{I}}_2 + {\mathrm{H}}_2{\mathrm{O}}_2 + 2{\mathrm{OH}}^{–}\to 2{\mathrm{I}}^{–}+ 2{\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$

$\mathrm{PbS}+4{\mathrm{H}}_2{\mathrm{O}}_2\to {\mathrm{PbSO}}_4+4{\mathrm{H}}_2\mathrm{O}$