Diego expects the market interest rate will keep decreasing in the future. Which of the following bond would give him the highest return based on his expectation? aved ouroll Select one: a. A 30-year zero coupon bond b. A 20-year 5% coupon bond c. A 2-year 10% coupon bond d. A 5-year 10% coupon bond e. A 3-year zero coupon bond