Assume that a firm has a cost of debt capital of 0.05, a company tax rate of 0.25, a market value of debt of $11 million, a cost of equity capital of 0.12, and a market value of equity of $14 million. Also assume that the proportion of company taxes claimed by shareholders is 0.8. Which of the following values is the closest to this firm's weighted average cost of capital?

a. 0.088

b. 0.078

c. 0.098

d. 0.108

e. 0.068