An Application Requires a Development Environment (DEV) and Production Environment

An application requires a development environment (DEV) and production environment (PROD) for several years. The DEV instances will run for 10 hours each day during normal business hours, while the PROD instances will run 24 hours each day. A solutions architect needs to determine a compute instance purchase strategy to minimize costs. Which solution is the MOST cost-effective?

A) DEV with Spot Instances and PROD with On-Demand Instances
B) DEV with On-Demand Instances and PROD with Spot Instances
C) DEV with Scheduled Reserved Instances and PROD with Reserved Instances
D) DEV with On-Demand Instances and PROD with Scheduled Reserved Instances