Which storage option meets these requirements MOST cost-effectively?

Explanations:

While storing logs in Amazon S3 and using AWS Backup to move logs to S3 Glacier Deep Archive is a valid approach, AWS Backup is not the most cost-effective option for managing lifecycle transitions of S3 objects. It is typically used for backing up data rather than lifecycle management.

Storing logs in Amazon S3 and using S3 Lifecycle policies to transition logs older than 1 month to S3 Glacier Deep Archive is the most cost-effective option. S3 Lifecycle policies automate the management of objects in S3, allowing for seamless and cost-efficient transitions to lower-cost storage options based on age.

Storing logs in Amazon CloudWatch Logs is not optimal since it incurs higher costs compared to S3 for long-term storage. Although AWS Backup can be used to move logs to S3 Glacier Deep Archive, CloudWatch is not designed for efficient long-term storage of large log files, especially when the retention period is 10 years.

While using CloudWatch Logs to store logs is an option, it is not cost-effective for long-term storage. Additionally, Amazon S3 Lifecycle policies cannot be applied directly to CloudWatch Logs. This option does not utilize S3’s capabilities effectively for the long-term retention required.