A. 4.21%.All spot rates are given on a BEY basis and must be divided by 2 in this calculation, orf = (1+(.028/2))^3 / (1+(.021/2))^2 -1 = .021036On a BEY basis, the forward rate is 0.021036 × 2=4.21%.The semiannual bond equivalent yield spot rates for US Treasury yields are provided below.Period Years Spot Rate1 0.5 1.20%2 1.0 2.10%3 1.5 2.80%4 2.0 3.30%On a semiannual bond equivalent yield (BEY) basis, the six-month forward rate one year from now is closest to:A. 4.21%.B. 3.64%.C. 2.10%.