You were hired as a consultant to Giambono Company, whose target capital structure is 40% debt, 15% preferred, and 45% common equity. The after-tax cost of debt is 6.00%, the cost of preferred is 7.50%, and the cost of retained earnings is 11.50%. The firm will not be issuing any new stock. What is its WACC? 8.70% 8.87% 7.92% 7.66% 6.70%