Please explain. TY

Jane Walker has set a 7% yield as the goal for the bond portion of her portfolio. To achieve this goal, she has purchased a 7% 15-year corporate bond at a discount price of 93.50. The bond's principal is 1000. What amount of reinvestment income will she need to earn over this 15-year period to achieve a compound return of 7 on a semiannual basis? % A. $459. B. $624. C. $574. Answer: C