Find the Weighted Average Cost of Capital for a Firm

Find the weighted average cost of capital for a firm that has a debt-to-equity ratio of 2,a tax rate of 40 percent,a levered cost of equity of 12 percent and a pre-tax cost of debt of 9 percent.

A) 7.6 percent
B) 7.968 percent
C) 10 percent
D) none of the options