To help finance a major expansion, Castro Chemical Company sold a noncallable bond several years ago that now has 20 years to maturity. This bond has a 9.25% annual coupon, paid semiannually, sells at a price of $1,025, and has a par value of $1,000. If the firm's tax rate is 40%, what is the component cost of debt for use in the WACC calculation? Do not round your intermediate calculations. a. 5.93% b. 5.39% C. 5.93% d. 4.69% e. 6.09%