The lead-acid battery charging process involves reversing the chemical reactions that occur during discharging. In a lead-acid battery, there are two electrodes: a lead dioxide (PbO2) cathode and a lead (Pb) anode, both immersed in an electrolyte of sulfuric acid (H2SO4). During the discharge process, at the anode (negative electrode), lead (Pb) is oxidized to lead sulfate (PbSO4) : Pb+SO42−⟶PbSO4+2e− At the cathode (positive electrode), lead dioxide (PbO2) is reduced to lead sulfate ( PbSO4 ) as well using the electrons that flow through the external circuit: PbO2+4H++SO42−+2e−⟶PbSO4+2H2O When the battery is being charged, these reactions are reversed. At the anode: PbSO4+2e−⟶Pb+SO42− This is where lead sulfate is converted back to metallic lead. And at the cathode: PbSO4+2H2O⟶PbO2+4H++SO42−+2e− Here, lead sulfate is converted back to lead dioxide. In this context, Option B is the correct answer. During the charging process, PbSO4 indeed gets converted to Pb and PbO2 according to the reactions described. To be specific, these reactions take place at the two different electrodes of the battery (lead sulfate at both electrodes being converted into lead and lead dioxide, respectively).