Interest rate risk is the largest risk in a bond manager's portfolio. Adding which of the following bonds will add the least interest rate risk to the portfolio? In other words, which bond has the lowest Macaulay duration?
Group of answer choices
9-year, 10% coupon bond
5-year, 12% coupon bond
5-year, 0% coupon bond
15-year, 14% coupon bond
Cannot tell from the information given