A company’s data scientists use Amazon SageMaker with datasets stored in Amazon S3. Data older than 45 days must be removed according to policy…

Amazon S3 Lifecycle configuration is the native, automated, and most efficient feature for managing object lifecycles, including expiration. A lifecycle rule can be configured to permanently delete objects a specified number of days after their creation. This directly enforces the policy to remove data older than 45 days without requiring custom code, complex orchestration, or additional costs associated with services like Lambda. It is the purpose-built, scalable solution provided by AWS for this exact use case.

B. Triggering a Lambda function on every object upload to scan and delete old data is highly inefficient, costly, and not a scalable approach for this task.

C. A scheduled Lambda function is more complex and costly than a native S3 Lifecycle rule and requires maintaining custom code to replicate a built-in S3 feature.

D. S3 Intelligent-Tiering is a storage class that automatically optimizes storage costs by moving objects between access tiers; it does not delete data based on age.

1. Amazon S3 User Guide, "Managing your storage lifecycle": This document explicitly describes using lifecycle rules for object expiration. It states, "You can define rules to schedule the deletion of objects after a specified period." The Expiration action is detailed as the mechanism to "specify when objects expire."

Source: AWS Documentation, Amazon S3 User Guide, Section: "Lifecycle configuration elements", Subsection: "Expiration action".

2. Amazon S3 User Guide, "Tutorial: Configuring a lifecycle rule for a versioning-suspended bucket": This tutorial provides a step-by-step example of setting up a lifecycle rule to permanently delete objects after a specific number of days, directly matching the question's requirement.

Source: AWS Documentation, Amazon S3 User Guide, Section: "Tutorials and examples", Subsection: "Example 1: Specifying an expiration action".

3. Amazon S3 User Guide, "Using S3 Intelligent-Tiering": This source clarifies the function of S3 Intelligent-Tiering. It states, "The S3 Intelligent-Tiering storage class is designed to optimize storage costs by automatically moving data to the most cost-effective access tier when access patterns change." This confirms it is for cost optimization, not data deletion.

Source: AWS Documentation, Amazon S3 User Guide, Section: "Amazon S3 storage classes".