The coupon rate on a debt issue is $8\%.$ If the yield to maturity on the debt is $10\%,$ what is the after$-$tax cost of debt in the weighted average cost of capital if the firm's tax rate is $35\%?$

Note: Round your answer to $2$ decimal places.

Multiple Choice

$8\mathrm{.}65\%$

$7\mathrm{.}85\%$

$6\mathrm{.}50\%$

$5\mathrm{.}15\%$