A company has a cost of equity of 15.22% and an unlevered cost of capital of 11.29%.The company has $20,117 in debt that is selling at par value.The levered value of the firm is $35,756, and the tax rate is 34%.What is the pre-tax cost of debt?

6.16%

6.33%

6.49%

6.66%

6.83%