The Beta Corporation asks you to determine its marginal cost of capital. Beta's current capital structure consists of 45% debt, 15% preferred stock and 40% common equity. The separate marginal costs of the various components of the capital structure are as follows: debt, after-tax 5.0 percent; preferred stock, 9 percent; retained earnings, 12 percent; and new common stock, 13.5 percent. If Beta has P15 million investible retained earnings, and Beta has an opportunity to invest in an attractive project that costs P60 million, what is the marginal cost of capital of Beta Corporation? 8.40 percent 9.88 percent 8.63 percent 9.00 percent