The core idea
Callable bonds give the issuer the right to redeem debt early, which changes the investor's expected cash flows when rates move.
What is happening underneath
When yields fall, the probability of a call can rise, limiting price appreciation and increasing reinvestment risk.
How investors should read it
The embedded option means simple duration and yield-to-maturity measures may be insufficient.
The same market move can carry different information depending on which maturity, issuer and risk premium is changing. Read the question together with the underlying concepts rather than treating one price move as a universal signal.