Amazon Inc. (AMZN) has 55 percent equity-to-asset ratio. The average yield to maturityon AMZN's bonds is 3.2. perent; assume a tax rate of 30 percent. The firms estimated required rate of return on equity is estimated at about 10.8 percent. WHat Amazons weighted average cost of capital (WACC) (round to the nearest tenth of a percent)

A. 6.6 percent

B. 7.3 percent

C. 6.1 percent

D. 6.9 percent