Immunization of coupon-paying bonds does not imply that the portfolio manager is inactive because: 1. The portfolio must be rebalanced every time interest rates change. 2. The portfolio must be rebalanced over time even if interest rates don't change. 3. Convexity implies duration-based immunization strategies don't work.

Immunization of coupon-paying bonds does not imply that the portfolio manager is inactive because: 1. The portfolio must be rebalanced every time interest rates change. 2. The portfolio must be rebalanced over time even if interest rates don't change. 3. Convexity implies duration-based immunization strategies don't work. 1 only 1 and 2 only 2 only 1,2 , and 3