Copper(II) oxide reacts with iron. The equation for this reaction is shown below. $3\text{CuO} + 2\text{Fe} \rightarrow 3\text{Cu} + \text{Fe}_2\text{O}_3$ Why may this reaction be described as the reduction of copper(II) oxide?
- AIron gains oxygen.
- BThe copper(II) oxide loses oxygen.
- CThe copper(II) oxide weighs less after the reaction than before.
- DThere are fewer substances on the right of the equation.