A company has an ML model in Amazon SageMaker AI.

Option A is correct because the requirement is to detect changes in the input data distribution of model features, which is a data quality / data drift monitoring problem. AWS documentation states that Amazon SageMaker Model Monitor uses rules to detect data drift and alerts you when it happens. The documented workflow is to enable data capture, create a baseline from training data, and then run monitoring jobs that compare incoming inference data against that baseline. That directly matches the need to automatically detect changes in feature distributions.

AWS also documents that Model Monitor can emit metrics to Amazon CloudWatch, and those metrics can be used with CloudWatch alarms to notify teams when data quality drifts beyond acceptable thresholds. That makes Option A the lowest-operational-overhead solution because it uses SageMaker’s built-in monitoring capability plus managed alerting, rather than requiring custom drift logic. The inclusion of emit_metrics and CloudWatch alarming is consistent with the SageMaker monitoring pattern for automated notification.

The other options are weaker. Option B is for model quality monitoring, which focuses on prediction performance against ground truth, not shifts in the input feature distribution. Option C uses SageMaker Debugger, which is aimed at training-time debugging and custom rule analysis rather than managed production data drift monitoring. Option D relies on manual log analysis and endpoint performance metrics, which does not directly solve feature-distribution drift detection and adds more operational effort. Therefore, the best AWS-documented answer is A.