Energy Inc. has a bond issue with a maturity of $15$ years, a coupon rate of $10\%$ and coupons paid annually. The face value of the issue sells for $92\mathrm{.}8\%$ of par value. The firm's tax rate is $30\%.$ What is the after$-$tax cost of debt?

Question $15$ options:

$10\mathrm{.}44\%$

$7\mathrm{.}70\%$

$9\mathrm{.}75\%$

$7\mathrm{.}31\%$