Suppose the U.S. Treasury offers to sell you a bond for $627.25. No payments will be made until the bond matures 6 years from now, at which time it will be redeemed for $1,000. What interest rate would you earn if you bought this bond at the offer price?

a. 9.78% b. 26.57% c. 6.89% d. 8.08% e. 7.24%