You were hired as a consultant to Giambono Company, whose target capital structure is 40% debt, 15% preferred, and 45% c ommon equity. The after-tax cost of debt is 6.00%, the cost of preferred is 7.50%, and the cost of retained earnings is 16.0 0%. The firm will not be issuing any new stock. What is its WACC? O a. 10.73% b. 8.69% c. 10.94% d. 8.26% e. 13.41%