You will archive data in Cloud Storage and users will access it quarterly. Choose the most cost-efficient storage class for this access pattern.

Coldline Storage is the most cost-efficient option for data accessed quarterly because it offers the lowest storage cost among all Cloud Storage classes. While it has higher data access and retrieval costs compared to Nearline, Regional, and Multi-Regional Storage, the infrequent quarterly access pattern minimizes these additional charges, making its low monthly storage cost the dominant factor in overall expense. Nearline Storage is designed for data accessed less than once a month, making it more expensive than Coldline for quarterly access. Regional and Multi-Regional Storage are for frequently accessed data (multiple times a month or more) and are significantly more expensive for archival purposes.