You will ingest objects once into a Cloud Storage bucket with random access patterns per object. You want to minimize storage and retrieval cost while keeping cost optimizations transparent to users and apps. What do you do?

Autoclass automatically transitions objects to the most cost-effective storage class based on access patterns, minimizing storage and retrieval costs without user intervention. This meets the requirement for cost optimization transparency. Lifecycle rules transitioning to Coldline after 30 days are less optimal because objects might still be frequently accessed within that period, incurring higher retrieval costs from Coldline, or they might be infrequently accessed sooner, wasting money in Standard. Transitioning when an object is "not live" is ambiguous and not a standard Cloud Storage lifecycle condition. Using two separate buckets and manually migrating objects adds operational overhead and complexity, failing the transparency and minimal management requirements.