capital structure is 56% common stock, 10% preferred stock, and 34% mon stock is 6%, the cost of preferred stock is 7%, and the pre-tax cost marginal tax rate of 35%, what is the IS. ABC Company's debt. The cost of com of debt is 6.5%. with a. 6.2796 b. 5.46% c. 5.50% d. 7.34%