You were hired as a consultant to Keys Company, and you were provided with the following data: Target capital structure: 48% debt, 29% preferred, and 23% common equity. The after-tax cost of debt is 4.5%, the cost of preferred is 5%, and the cost of retained earnings is 9.5%. The firm will not be issuing any new stock. What is the firm's WACC? 6.40% 6.10% 5.50% 5.80% O 6.70%