Which statement is true?
A. In a reaction, oxidation can occur independently of reduction.
B. A redox reaction involves either the transfer of an electron or a change in the oxidation state of an element.
C. In a redox reaction, any increase in the oxidation state of a reactant must be accompanied by a decrease in the oxidation state of a reactant.
D. If any of the reactants or products in a reaction contain oxygen, the reaction is a redox reaction.