Which feature ensures that archived data in Glacier cannot be deleted or modified for a set retention period?

The feature that ensures that archived data in Amazon Glacier cannot be deleted or modified for a set retention period is referred to as Vault Lock. This capability allows users to impose compliance controls on their archives, ensuring data immutability for regulatory and governance purposes. When a Vault Lock is configured, it creates a policy that enforces write-once read-many (WORM) storage on the data stored within that vault, which helps in fulfilling legal and compliance requirements where data must remain unchanged for a specific duration.

In contrast, while Object Lock is commonly associated with Amazon S3, it does not apply to Glacier in the same way. Object Lock provides similar functionality for S3 objects, but for Glacier, Vault Lock serves as the correct mechanism to prevent modification or deletion of archived data. Other options such as Data Auditing and Content Delivery Control do not pertain to the retention characteristics of archived data in Glacier, making Vault Lock the appropriate choice in this context.