Question $7$

Stackelberg Inc. has issued $20-$year bond with a $7\mathrm{.}00\%$ annual coupon, paid semiannua marginal tax rate is $40\mathrm{.}00\%,$ but there a possibility of a change in the corporate tax rat

By how much would the after tax cost of debt used to calculate the WACC change if $t$

$0\mathrm{.}61\%$

$0\mathrm{.}52\%$

$0\mathrm{.}73\%$

$0\mathrm{.}82\%$