Suppose you have a one year old child and you want to make an investment for future education expenses on your child's 18th birthday. Which of the following investments would be the most appropriate if you want to avoid the effects of changes in interest rates between now and the time your child enters college?
a. A 20 year 8% coupon bearing bond.
b. A 20 year zero coupon bond.
c. A 17 year 8% coupon bearing bond.
d. A 17 year 5% coupon bearing bond.
e. A 17 year zero coupon bond.