Hi-Octane Oil Company has a debt-equity ratio of 0.25. The company uses no preferred stock in its capital structure. If the cost of equity is 14.4% and the after-tax cost of debt is 6.2%, what is the company's weighted average cost of capital?
a. 6.20
b. 8.25%
c. 12.35%
d. 12.76%
e. 14.4%