Your company creates a custom Azure Machine Learning model that uses a generative AI assistant.

A common reason models degrade after being successful in production is data drift (also called concept drift). Over time, the distribution of input data changes—for example, customer behavior shifts, product catalog changes, seasonality changes, new categories appear, sensors get recalibrated, or business processes evolve. When the model sees data that differs from what it was trained on, its predictions can become less accurate. This is exactly what option A describes and is the most likely “six months later” cause.

Option B is not a primary explanation for reduced predictive accuracy. More compute can improve throughput/latency, but it does not inherently improve correctness of predictions. If anything, compute constraints typically cause timeouts or slower responses, not a systematic accuracy drop.

Option C (trained incorrectly) would usually manifest earlier—poor performance from the start—unless the “incorrectness” is that the model was trained on a snapshot that later became stale (which again maps back to drift). The correct operational response is to monitor for drift, validate performance regularly, and retrain/refresh the model using newer representative data and updated features/labels.