Azure Blob Storage Cool tier is designed for data that is infrequently accessed and stored for at least 30 days. It offers lower storage costs than the Hot tier, making it a cost-effective solution for long-term storage of infrequently accessed data. In contrast, Azure Blob Storage Hot tier is optimized for frequently accessed data and incurs higher costs, which is not suitable for the given scenario. Azure File Storage provides SMB-based file shares and is designed for lift-and-shift scenarios for legacy applications that require file shares, not for long-term data retention. Azure Queue Storage is used mainly for storing large numbers of messages that can be accessed from anywhere in the world, which is not the focus of the scenario described.