A corporate bond has a face value of $1,000 and a coupon rate of 9.5%. The bond matures in 12 years and has a current market price of $1,100. If the corporation sells more bonds it will incur flotation costs of $48 per bond. If the corporate tax rate is 35%, what is the after-tax cost of debt capital?

5.71%

5.91%

6.18%

5.31%