During discharging the change taking place at cathode in lead accumulator is

• A

  $\mathrm{Pb}_{(\mathrm{s})}$ is oxidised to $\mathrm{Pb}_{(\text {aq. } .}^{2+}$
• B

  $\mathrm{Pb}_{\text {(aq.) }}^{2+}$ is oxidised to $\mathrm{PbO}_{2(\mathrm{~s})}$
• Correct answer
  C

  $\mathrm{Pb} \mathrm{O}_{2(\mathrm{~s})}$ is reduced to $\mathrm{Pb}_{(\text {aq. })}^{2+}$
• D

  $\mathrm{Pb}_{\text {(aq.) }}^{2+}$ is reduced to $\mathrm{Pb}_{(\mathrm{s})}$

Hence, the correct answer is option: 'C'.