Debreu Beverages has an optimal capital structure that is 70% common equity, 20% debt, and 10% preferred stock. Debreu's pretax cost of equity is 9%. Its pretax cost of preferred equity is 7%, and its pretax cost of debt is also 5%. If the corporate tax rate is 35%, what is the weighed average cost of capital?

A. Between 7% and 8%

B. Between 8% and 9%

C. Between 9% and 10%

D. Between 10% and 12%