Rollins Corporation is constructing its MCC schedule. Its target capital structure is 20 percent debt, 20 percent preferred stock, and 60 percent common equity. Its bonds have a 12 percent coupon, paid semiannually, a current maturity of 20 years, and sell for $1,000. The firm's marginal tax rate is 35 percent. Which of the following is Rollins' after-tax cost of debt? (Round off the answer to one decimal place.)

Group of answer choices

c. 6.8 percent

a. 7.8 percent

b. 7.0 percent

d. 5.3 percent

e. 9.5 percent