Consider an enterprise with a capital structure consisting of $60\%$ debt and $40\%$ equity. If you use the costs of debt and equity of the company from Question $1$ and $2,$ what would be the company's WACC? Assume a marginal tax rate is $15\%.$

$6\mathrm{.}9\%$

$7\mathrm{.}56\%$

$6\mathrm{.}5\%$

$8\mathrm{.}02\%$