A company stores petabytes of data in Amazon S3 Standard across multiple buckets with unknown access patterns. The company needs a per-bucket solution to optimize S3 cost with the most operational efficiency. Which solution meets these requirements?

S3 Intelligent-Tiering is designed for unknown or changing access patterns, automatically moving objects between frequent and infrequent access tiers to optimize costs without performance impact or operational overhead. This perfectly matches the requirement for optimizing cost with the most operational efficiency for petabytes of data with unknown access patterns. S3 storage class analysis provides recommendations but requires manual intervention to move objects, which is not operationally efficient for petabytes of data. S3 Glacier Instant Retrieval is for data accessed once a quarter or less, and S3 One Zone-IA is for infrequently accessed, non-critical data that can be recreated, neither of which is suitable given the unknown access patterns and the need for high operational efficiency without making assumptions about access frequency or data criticality.