A corporate bond has a face value of $1,000 and a coupon rate of 5%. The bond matures in 20 years and has a current market price of $900. If the corporation sells more bonds, it will incur flotation costs of $25 per bond. If the corporate tax rate is 35%, what is the after-tax cost of debt capital?

3.81%

4.45%

5.29%

6.78%