Which One of the Following Statements Related to Corporate Taxes

Which one of the following statements related to corporate taxes is correct?

A) A company's marginal tax rate must be equal to or lower than its average tax rate.
B) The tax for a company is computed by multiplying the marginal tax rate times the taxable income.
C) Additional income is taxed at a firm's average tax rate.
D) The marginal tax rate will always exceed a company's average tax rate.
E) The marginal tax rate for a company can be either higher than or equal to the average tax rate.