Assume that investors hold Amazon stock in retirement accounts that are free from personal taxes. Also assume that Amazon's current pre-tax WACC is 20%. and a corporate tax of 25%. If Amazon were to issue sufficient debt at a pre-tax cost of 7% to give them a debt to value ratio of 0.5, then the Amazon's after-tax WACC would be closest to: Select one: O A. 13.0% O B. 14.13% O C. 16.0% O D. 15.0% O E. 19.13%