Assume that all interest rates in the economy decline from 10 percent to 9 percent. Which of the following bonds will have the largest percentage increase in price? Select one: a. A 13-year zero coupon bond. b. A 1-year bond with a 15% coupon. O c. An 8-year bond with a 9% coupon. O d. A 10-year zero coupon bond. O e. A 10-year bond with a 10% coupon