GHJ Inc.'s semi-annual bonds have a price of $770, an 9.40% coupon rate and mature in 18 years. The company's tax rate is 33%. What is its after-tax cost of debt when calculating its WACC?

a.

6.30%

b.

12.67%

c.

9.40%

d.

4.25%

e.

8.49%