Which EC2 instance purchasing solution will meet the company’s requirements MOST cost-effectively?

Explanations:

Spot Instances are not suitable for production workloads due to their potential for interruption. While they can save costs for non-critical workloads, using Reserved Instances for the development and test environments is more cost-effective given their regular usage.

Reserved Instances provide a significant discount for the production environment, which runs continuously. On-Demand Instances for development and test allow flexibility in scaling and automating instance management, leading to cost savings since they run for a limited time daily.

Spot blocks offer a way to reserve Spot Instances for a fixed duration but are still subject to interruption. Using them for production workloads is risky, while Reserved Instances for development and test environments is a better approach for regular usage.

On-Demand Instances for production are more expensive than Reserved Instances. Using Spot blocks for development and test may save costs, but it does not provide the reliability required for production workloads, making this option less cost-effective overall.