Your company has a target capital structure of 40% debt, 15% preferred, and 45% common equity. Your bonds carry a 9% coupon, have a par value of $1,000, and 7 years remaining until maturity. They are currently selling for $950.51. The cost of preferred is 7.50%. The risk free rate is 4%, the market risk premium is 8%, and beta is 1.0. The firm will not be issuing any new stock, and the tax rate is 40%. What is its WACC?

a. 6.96% b. 8.93% c. 7.68% d. 7.59% e. 6.69%