Cold Boxes Ltd. bonds have a par value of $1000. The required rate of return on these bonds is currently 10 percent; interest is paid semiannually. The bonds mature in 5 years, and their current market value is $768.40 per bond. What is the annual coupon interest rate for the bonds?

a. 8%

b. 6%

c. 4%

d. 2%

e. 0%