A business has a cost of equity of 9.5 percent and a pretax cost of debt of 5.4 percent. The debt-equity ratio is 0.75 and the tax rate is 25 percent. What is the unlevered cost of capital

a. 7.76%

b. 7.89%

c. 8.02%

d. 8.15%

e. 8.28%