If its yield to maturity declined by 1%, which of the following bonds would have the largest percentage increase in value?

a. A 1-year zero coupon bond.
b. A 10-year bond with a 12% coupon.
c. A 10-year zero coupon bond.
d. A 1-year bond with an 8% coupon.
e. A 10-year bond with an 8% coupon.