On Amazon EC2, a business hosts an ecommerce application. The application is composed of a
stateless web layer that needs a minimum of 10 instances and a maximum of 250 instances to run.
80% of the time, the program needs 50 instances.
Which solution should be adopted in order to keep expenses down?
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.
