Which of the following statements is CORRECT?

A$.$ The WACC is calculated using after$-$tax costs for all components.

B$.$ The after$-$tax cost of debt usually exceeds the after$-$tax cost of preferred stock.

C$.$ For a given firm, the after$-$tax cost of preferred stock is always more expensive than the after$-$tax cost of common equity.

D$.$ The WACC that should be used in capital budgeting is the firm$$s marginal, before$-$tax cost of capital.