The correct option is Soft Delete for Azure Files.

Soft Delete for Azure Files preserves deleted files and directories for a configurable retention period and lets you restore them within that window, so it meets the requirement to recover deleted files for 15 days.

Azure File Share snapshots create point in time copies of a file share but they must be created before a deletion and they do not provide an automatic retention window for deleted items, so they do not directly satisfy a 15 day automatic recovery requirement.

Blob versioning applies to blob storage and tracks versions of blobs, so it does not apply to Azure Files and cannot be used to recover deleted files in a file share.

Blob lifecycle management is used to automate tiering and deletion policies for blobs and it does not provide file share deletion recovery nor does it apply to Azure Files.

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