For a particular firm, the purchasers of common stock require an 11% rate of return, bonds are sold at a 7% interest rate and bank loans are available at 9%. The firm has a 38% combined tax rate. For the next year money available through common stock, bonds and bank loans is shown below. Funds Source Rate available Commons $40 stock 11% Million $20 Bonds 7% Million Bank $60 9% loans Million The after-tax weighted cost of capital for this firm is most nearly: 6.9% 7.2% 9.0% 9.3%