Walker is another bond manager at Legacy Trust. He is managing U.S. bond and also observe the current yield curve below. Yield Curve 3.00% 2.00% 1.00% 0.00% -1.00% Im 3m 6m ly 24 Current 3y 4y 5y Year Ago 10y 15y 20y 30y Walker has the following bonds in this portfolio: Bond A: 20-year bond with 3% coupon rate. Bond B: 5-year bond with 5% coupon rate. Bond C: 2-year bond with 10% coupon rate. Bond D: 15-year bond with 2% coupon rate. All bonds are semi-annual paying bonds with $1,000 par value. In addition, Walker earns a 5% yield to maturity for all of the above bonds. Given that Walker observes the yield curve trend as seen in this problem and he is considering selling most of the bonds in his portfolio such that he only has one type of bond remaining, which one of the above 4 bonds (A, B, C, or D) would you recommend Boo to KEEP and more importantly, why?