A company is running an ecommerce application on Amazon EC2. The application consists of a stateless web tier that requires a minimum of 10 instances, and a peak of 250 instances to support the application's usage. The application requires 50 instances 80% of the time.
Which solution should be used to minimize costs?

A. Purchase Reserved Instances to cover 250 instances. B. Purchase Reserved Instances to cover 80 instances. Use Spot Instances to cover the remaining instances. C. Purchase On-Demand Instances to cover 40 instances. Use Spot Instances to cover the remaining instances. D. Purchase Reserved Instances to cover 50 instances. Use On-Demand and Spot Instances to cover the remaining instances.