General Motors is contemplating to recapitalize the firm and raise additional capital. Its current capital structure has a 30% weight in equity, 15% in preferred stock, and 55% in debt. The cost of equity capital is 20%, the cost of preferred stock is 15%, and the pretax cost of debt is 10%. What is the weighted average cost of capital for Ford if its marginal tax rate is 40%? Select one: O a. 11.55% O b. 10.28% O c. 13.05% O d. 9.34%