A company has a cost of equity of 14.98% and an unlevered cost of capital of 11.06%. The company has $19,680 in debt that is selling at par value. The levered value of the firm is $34,987, and the tax rate is 33%. What is the pre-tax cost of debt?

a) 6.35

b) 6.51

c)7

d) 6.67

e) 6.83