Central Systems desires a weighted average cost of capital of 12.7 percent. The firm has an aftertax cost of debt of 4.8 percent and a cost of equity of 15.4 percent. What debt-equity ratio is needed for the firm to achieve its targeted weighted average cost of capital?

a. 0.37
b. 0.44
c. 0.42
d. 0.56
e. 0.34