Marginal Incorporated (MI) has determined that its after-tax cost of debt is 10.0%. Its cost of preferred stock is 14.0%. Its cost of internal equity is 16.0%, and its cost of external equity is 19.0%. Currently, the firm's capital structure has $325 million of debt, $50 million of preferred stock, and $125 million of common equity. The firm's marginal tax rate is 45%. The firm is currently making projections for the next period. Its managers have determined that the firm should have $62 million available from retained earnings for investment purposes next period. What is the firm's marginal cost of capital at a total investment level $223 milion? 9.73% 12.65% 12.28% 11.90% 8.98%