Final answer:
io1 EBS volumes are best suited for high-performance critical business applications requiring more than 10000 IOPS and sub-millisecond latency, such as database workloads and big data analytics engines.
Step-by-step explanation:
The use case that suits using io1 EBS volumes is when applications require high performance and low latency with provisioned Input/Output Operations Per Second (IOPS). These volumes are designed mainly for critical business applications that need sustained IOPS performance, or more than 10000 IOPS, and sub-millisecond latency. In particular, io1 volumes work well for applications such as high-volume database workloads, big data analytics engines, and other transaction-heavy workloads that benefit from high durability and consistent IOPS performance.