To help finance a major expansion, Large Hadron Company sold a noncallable bond 10 years ago that now has 15 years to maturity. This bond has a 7.25% annual coupon, paid semiannually, sells at a price of $1,125, and has a par value of $1,000. If the firm's tax rate is 35%, what is the component (post-tax) cost of debt for use in the WACC calculation? 5.97% 6.25% 3.88% 4.06% 4.71%