the oxidation states of the elements before and after the reaction is; Pb oxidation state changes from 0 to +2 SO₄²⁻ ion there's no change in the oxidation state during the reaction Au oxidation state changes from +3 to 0 reduction reactions are when there's a decrease in the oxidation state of the species oxidation reactions are when theres an increase in the oxidation state of the species the element where there's a decrease in oxidation state is Au. Therefore Au gets reduced. answer is B) Au
