The Corporate Tax Schedule Seems Not to Be Progressive

The corporate tax schedule seems not to be progressive. Which statement is correct?

A) The idea of progressive taxes refers only to individuals, the corporate schedule is intentionally not progressive.
B) The corporate schedule is indeed not progressive because the rates do not increase steadily as income increases.
C) Corporate Taxes are progressive because the more money a corporation makes, the more taxes it pays.
D) Corporate taxes are conceptually progressive. The ups and downs in the schedule are designed to take away the benefit of low early rates for companies with large incomes.