Other things being equal, which of the following statements about interest rate risk is correct?

Select one:

a. A bond paying a 4% coupon rate is more risky than a bond with a 7% yield to maturity.

b. A zero coupon bond is less risky than a coupon-paying bond.

c. A bond paying a 4% coupon rate is more risky than a bond paying a 2% coupon rate.

d. A bond paying a 7% coupon rate is less risky than a bond paying a 5% coupon rate.