S3 Standard is appropriate for temporary files that will be processed and moved quickly because it has no minimum storage-duration charge. S3 Standard-IA would be inefficient for short-lived temporary objects because it applies minimum storage-duration and minimum billable object-size considerations. S3 Event Notifications can invoke Lambda directly when objects are created, enabling event-driven preprocessing without polling. Lambda event source mappings are used with supported stream and queue sources, such as Amazon SQS or Kinesis, rather than directly with S3 buckets. Combining very small files into a larger ZIP archive reduces the number of archived objects, retrieval requests, and per-object metadata overhead associated with archival storage. Moving each small file to S3 One Zone-IA would add an unnecessary intermediate tier and provide lower resilience before archival. Therefore, A, B, and D form the most economical workflow.

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