On May 23, 20XX, the existing or current (spot) one-year, two-year, three-year, and four-year zero-coupon Treasury security rates were as follows:

1R1 = 5.60%,

1R2 = 6.10%, 1R3 = 6.60%,

1R4 = 6.80%

Using the unbiased expectations theory, what is the one-year forward rate on zero-coupon Treasury bonds for year four as of May 23, 20XX

6.80%

7.40%

23.20%

6.275%