Bond price sensitivity to changes in market interest rates increases as maturity becomes longer and the coupon rate becomes lower . The IFC material specifically explains that price sensitivity rises as term to maturity increases and coupon decreases. Accordingly, the 15-year bonds are more sensitive than the 5-year bonds because investors must wait considerably longer for principal repayment. Between the two 15-year securities, the 4% coupon bond is more sensitive than the 6% coupon bond because a larger proportion of its value is represented by the distant principal payment rather than nearer-term coupon cash flows. When interest rates rise, those distant cash flows are discounted at the new higher rate, producing a larger price decline. Therefore, the 4% coupon 15-year bond has the greatest interest-rate risk, making D correct.

================