You were hired as a consultant to Giambono Company, whose target capital structure is 50% debt, 15% preferred, and 35% common equity. The after-tax cost of debt is 6.00%, the cost of preferred is 9.00%, and the cost of retained earnings is 13.00%. The firm will not be issuing any new stock. What is its WACC?

a. 8.90%

b. 5.90%

c. 9.33%

d. 7.55%

e. 4.35%