Which Amazon EC2 instance purchasing options meet these requirements MOST cost-effectively?

Explanations:

On-Demand Instances are flexible but can be more expensive for steady, predictable workloads compared to other options like Reserved Instances.

Reserved Instances offer a significant discount for committing to a long-term usage (1 or 3 years) and are ideal for steady, predictable workloads.

Spot Instances are designed for workloads that can tolerate interruptions and are not suitable for uninterruptible workloads due to their variable availability.

Savings Plans provide flexible pricing over a commitment period and can also reduce costs for steady workloads, making it a suitable option.

Dedicated Hosts are more about physical server allocation rather than cost savings and are not the most cost-effective for steady workloads compared to Reserved Instances.