What Is "Double Taxation" in the Context of a Corporation

What is "double taxation" in the context of a corporation?

A) Consumers are taxed twice, once when they purchase products and once when they receive dividend cheques.
B) The federal government taxes corporate earnings at twice the rate of earnings of sole proprietors.
C) Gross earnings are taxed, then net earnings.
D) A corporation must pay income taxes on its profits, and then shareholders must also pay personal income taxes on the dividends they receive from the corporation.
E) None of these explain double taxation.