Marginal Incorporated (MI) has determined that its after-tax cost of debt is 9.0%. Its cost of preferred stock is 15.0%. Its cost of internal equity is 17.0%, and its cost of external equity is 19.0%. Currently, the firm's capital structure has $378 million of debt, $63 million of preferred stock, and $459 million of common equity. The firm's marginal tax rate is 45%. The firm is currently making projections for next period. Its managers have determined that the firm should have $92 million available from retained earnings for investment purposes next period. What is the firm's marginal cost of capital at a total investment level of $157 million?

a.

14.01%

b.

14.52%

c.

11.80%

d.

13.50%

e.

12.82%