An investor purchased a fixed-coupon bond at a time when the bond's yield to maturity was 6.9%. The investor sold the bond prior to maturity and realized a total return of 7.1%. Which of these most likely occurred while the investor owned the bond?

a. Market interest rates declined.
b. Market interest rates increased.
c. The inflation rate increased.
d. The bond's current yield increased above the bond's coupon rate.