You were hired as a consultant to Locke Company, and you were provided with the following data: Target capital structure: $40\%$ debt, $10\%$ preferred, and $50\%$ common equity. The interest rate on new debt is $7\mathrm{.}5\%,$ the yield on the preferred is $7\mathrm{.}0\%,$ the cost of retained earnings is $11\mathrm{.}50\%,$ and the tax rate is $40\%.$ The firm will not be issuing any new stock. What is the firm$$s WACC?

A$)8\mathrm{.}25\%$

B$)8\mathrm{.}50\%$

C$)7\mathrm{.}5\%$

D$)11\mathrm{.}5\%$