Stackelberg Inc. has issued 20-year bond with a 7.00% annual coupon, paid semiannually and a $1,000 par value. The company's marginal tax rate is 40.00%, but there a possibility of a change in the corporate tax rate to 30.00%.

By how much would the after tax cost of debt used to calculate the WACC change if the new tax rate was adopted?

Group of answer choices

0.82%

0.61%

0.73%

0.70%

0.52%