Consider the reaction in a lead storage battery below. Which of the following statements is correct?

PbO_2(s) + Pb(s) + 2 H2SO4(aq) ⇌ 2 PbSO4(s) + 2 H2O(l)
a) Lead is reduced
b) Sulfur is oxidized
c) Oxygen is reduced
d) Hydrogen is oxidized