AI models are not " static " systems; they are reflections of the data they were trained on. In dynamic environments, data patterns change constantly (e.g., market trends or new fraud tactics). Frequent testing and retraining ensure the model is " updated with current data, " which prevents performance degradation and " data drift. " While testing can assess attacks (Option A), the primary operational reason for a recurring retraining schedule is to maintain the model ' s relevance and accuracy against the most recent real-world behaviors.