Delta, Inc. has a stock price of $50. In the fiscal year just ended, dividends were $2.00. Earnings per share and dividends are expected to increase at an annual rate of 8 percent. The risk-free rate is 4 percent, the market risk premium is 6.4 percent, and the beta on Delta's stock is 1.25. Delta's target capital structure is 40% debt and 60% common equity. Delta's tax rate is:

a. 25%
b. 30%
c. 35%
d. 40%