The correct answer is: C. Neither A nor B.
WACC stands for Weighted Average Cost of Capital. It is a measure of a company’s overall cost of capital, taking into account the different types of financing it uses. The WACC is calculated by weighting the cost of each type of financing by its proportion of the total capital structure.
In the case of an all-equity financed firm, there is no debt financing, so the WACC would be equal to the cost of equity. The cost of equity is the rate of return that investors require on their investment in the firm. It is calculated by taking into account the risk of the firm and the return that investors could earn on other investments of similar risk.
The cost of debt is the rate of interest that a firm pays on its borrowings. It is typically lower than the cost of equity, because debt is a less risky form of financing. The cost of debt is calculated by taking into account the interest rate on the debt, the maturity of the debt, and the risk of default.
When a firm has both debt and equity financing, the WACC is calculated by weighting the cost of each type of financing by its proportion of the total capital structure. The cost of debt is weighted by the proportion of debt in the capital structure, and the cost of equity is weighted by the proportion of equity in the capital structure.
In the case of an all-equity financed firm, there is no debt financing, so the WACC would be equal to the cost of equity.