Firm X has some outstanding debt that has a total face value of $500 million and currently sells for 105 percent of face value. The yield-to-maturity on the debt is 9.12 percent. The firm also has 5.6 million shares of common stock outstanding at a price per share of $47 and a required rate of return of 13.1 percent, Besides bonds and common shares, the firm has 3 million shares of preferred stock outstanding at a price of $40 a share. The cost of preferred stock is 7%. What is the firm's weighted average cost of capital if the tax rate is 34 percent?

a) 8.20% b) 9.99% c) not enough info d) none