AWS S3 Glacier Deep Archive is the most cost-effective storage option provided by AWS for long-term data archiving where data is retrieved infrequently and retrieval times of 12 hours or longer are acceptable. S3 Standard and S3 Intelligent-Tiering are not optimized for such specific long-term archiving needs, and they incur higher storage costs compared to Glacier Deep Archive. S3 One Zone-IA is cost-effective for infrequently accessed data, but not as much as Glacier Deep Archive for long-term archiving.