Keys Printing plans to issue a $1,000 par value, 20-year noncallable bond with a 7.00% annual coupon, paid semiannually. The company's marginal tax rate is 40.00%, but Congress is considering a change in the corporate tax rate to 25.00%. By how much would the component cost of debt used to calculate the WACC change if the new tax rate was adopted? Do not round your intermediate calculations. a. 1.72% b. 1.39% c. 1.05% d. 1.92% e. 1.78%