As a fixed income portfolio manager at a large asset management firm, you are tasked with adjusting the duration of your portfolio in anticipation of changing interest rates. Currently, your portfolio has a modified duration of 5 years, and you are concerned that a potential rate hike by the central bank will adversely affect the value of your bonds. You are considering the following options to mitigate interest rate risk:
1. Shorten the portfolio's duration by selling longer-term bonds and replacing them with shorter-term bonds.
2. Implement a bond swap strategy, exchanging high-coupon bonds for zero-coupon bonds of equivalent duration.
3. Create a laddered bond portfolio that involves staggering the maturity dates of bonds.
Which of these strategies will most effectively reduce the portfolio's exposure to interest rate risk?