The relative market values of a company's sources of capital are 50% debt, 10% preferred stock, and 40% common stock.The company's current cost of preferred stock is 8%, common stock is 12%, and pre-tax cost of debt is 6.5%.The company has an income tax rate of 25%.What is the company's WACC?

a.8.04%

b.8.68%

c.8.85%

d.9.49%