Ninecent Corporation has a target capital structure of 60 percent common stock, 5 percent preferred stock, and 35 percent debt. its cost of equity is 11 percent, the cost of preferred stock is 5 percent, and the pretax cost of debt is 6 percent. The relevant tax rate is 23 percent. a. What is the company's WACC? (Do not round intermediate calculations and enter your onswer as a percent rounded to 2 decimal places, e.g., 32.16.) b. What is the aftertax cost of debt? (Do not round intermediate calculations and enter your answer as o percent rounded to 2 decimal places, e.g., 32.16.)