A company currently stores 5 TB of data in on-premises block storage systems. The company's current storage solution provides limited space for additional data. The company runs applications on premises that must be able to retrieve frequently accessed data with low latency. The company requires a cloud-based storage solution. Which solution will meet these requirements with the MOST operational efficiency?

The correct solution is to use an AWS Storage Gateway Volume Gateway with cached volumes as iSCSI targets. This option provides a low-latency, on-premises cache for frequently accessed data while asynchronously storing all data in Amazon S3. This meets the requirement for low-latency retrieval for on-premises applications and provides a scalable cloud-based storage solution for the 5 TB of data, offering high operational efficiency. Using Amazon S3 File Gateway is incorrect because it provides file-level access (SMB/NFS) to S3, which is not ideal for block storage migration where iSCSI is typically used. Using stored volumes with Volume Gateway is incorrect because it stores the entire dataset on-premises, which doesn't address the limited on-premises space and primarily uses the cloud for backups, not primary storage. Tape Gateway is incorrect as it's designed for archival and backup, not for frequently accessed, low-latency data retrieval by active applications.