Answer:
Option b. is correct.
Step-by-step explanation:
A 10-year Treasury bond has an 8% coupon, and an 8-year Treasury bond has a 10% coupon. Neither is callable, and both have the same yield to maturity. If the yield to maturity of both bonds increases by the same amount, both bonds would decline in price, but the 10-year bond would have a greater percentage decline in price.
Option b. is correct.