A Firm Has Outstanding Debt with a Coupon Rate of 9

A firm has outstanding debt with a coupon rate of 9%, nine years' maturity, and a price of $1 000 per $1 000 face value. What is the after-tax cost of debt if the marginal tax rate of the firm is 30%?

A) 5.9%
B) 5.8%
C) 4.9%
D) 6.3%