6) Which of the following statements is true regarding the estimation of a firm's weighted average cost of capital, WACC?

Select one:

a. WACC should be estimated as an embedded (historical) cost of capital on a before-tax basis

b. WACC should be estimated as an embedded (historical) cost of capital on an after-tax basis

c. WACC should be estimated as a marginal cost of capital on a before-tax basis

d. WACC should be estimated as a marginal cost of capital on an after-tax basis