Company X has provided the following information about its current capital structure:

Debt: The firm just issued an 8-year, $1,000 par value, 6 percent (paid semi-annual) coupon bond. The current mark price of the bond is $985, and there are 1,000 bonds outstanding. The firm has a marginal tax rate of 36 percent.

Common Stock: A firm's common stock is currently selling for $92 per share, and there are 7,138 shares oustanding. The most recent dividend paid was $9. Dividends are expected to grow at a constant 5% rate indefinitely.

Given the information above, calculate the following (show work):

a. Calculate the firm's after-tax cost of debt

b. Calculate the cost of existing common sock

c. Calculate the firm's WACC