Thorstein Company has a targeted capital structure of 45% debt, 5% preferred stock, and 50% common equity. The company's cost of debt is 8.5%, preferred stock 7% and common equity 11%. They have a marginal tax rate of 25%. Which of the following most closely approximates Thorstein's WACC? O a. 8.7% O b. 9.4% O c 11.9% O d. 12.2% O e 19.9%