Which storage solution will meet these requirements MOST cost-effectively?

Explanations:

S3 Intelligent-Tiering is designed for data with unpredictable access patterns. While it can automatically move objects between two access tiers, it is not the most cost-effective solution for data that is accessed frequently for only a month and then rarely afterward.

Creating a Lifecycle configuration to transition objects from S3 Standard to S3 Glacier Deep Archive after 1 month is the most cost-effective solution for long-term storage. S3 Glacier Deep Archive is optimized for data that is infrequently accessed and is the lowest-cost storage option for indefinite retention.

Transitioning objects to S3 Standard-IA after 1 month would not be cost-effective because it is still relatively expensive compared to Glacier options. Standard-IA is suitable for infrequently accessed data but is not the best choice for indefinite retention.

While transitioning objects to S3 One Zone-IA could reduce costs compared to Standard-IA, it still does not offer the lowest cost for long-term storage, which is S3 Glacier Deep Archive. Additionally, One Zone-IA does not provide the same level of redundancy as other S3 storage classes.