Regime-switching dynamics are specifically designed to handle abrupt changes in economic conditions, such as sudden shifts in monetary policy. By allowing the model to transition between different regimes (e.g., low-interest-rate environments vs. high-inflation periods), it can adapt to unexpected policy changes more effectively than the other features.

A is Incorrect. While mean reversion stabilizes long-term projections by assuming rates revert to an average, it does not address sudden, unexpected shifts in monetary policy. Mean reversion works over longer horizons and may lag behind abrupt changes.

B is Incorrect. Stochastic volatility captures fluctuations in interest rate variability but does not directly address abrupt shifts caused by policy changes. It focuses on modeling uncertainty rather than regime transitions.

D is Incorrect. Fixed yield assumptions are overly simplistic and fail to account for any dynamic changes in interest rates, let alone sudden policy shifts. This makes them unsuitable for addressing the challenge described.