Which of the following statements is CORRECT? A) The WACC that should be used in capital budgeting is the firm's marginal, after-tax cost of capital. B) The WACC is calculated using before-tax costs for all components C) The after-tax cost of debt usually exceeds the after-tax cost of equity. D) For a given firm, the after-tax cost of debt is always more expensive than the after-tax cost of non-convertible preferred stock