Based on current market values, Shawhan Supply 's capital structure is 30% debt, 20% preferred stock, and 50% common stock. The required return on each component is: debt,8% before tax; preferred stock, 11%; and common stock, 18%. The marginal tax rate is 35%. What is firm's WACC? 9.76% 10.0% 13.60% None of them 12.76%