the answer is C I need the calculations

Chapter 9: A. The market value of Charcoal Corporation's common stock is $20 million, and the market value of its risk-free debt is $5 million. The beta of the company's common stock is 1.25, and the market risk premium is 8 percent. If the Treasury bill rate is 5 percent, what is the company's cost of capital? (Assume no taxes.) A. 15.0 percent B. 14.6 percent C. 13.0 percent D. 7.0 percent