A company has large datasets that auditors access only twice per year. Which Amazon S3 storage class will store the data at the lowest cost?

Amazon S3 Glacier Instant Retrieval is the most cost-effective solution for data accessed infrequently (twice per year) that requires immediate retrieval. It offers low storage costs with millisecond retrieval times, making it ideal for archival data that still needs quick access. Amazon S3 Outposts extends S3 storage to on-premises environments and is not primarily a cost-saving solution for infrequent access. Amazon S3 Standard is designed for frequently accessed data and would be significantly more expensive for this use case. Amazon S3 Intelligent-Tiering automatically moves data between access tiers based on access patterns but would likely transition the data to a lower-cost tier only after a period of inactivity, and S3 Glacier Instant Retrieval offers a lower baseline cost for known infrequent access.