A company maintains a stateless web application that is experiencing inconsistent traffic. The company uses AWS CloudFormation to deploy the application.
The application runs on Amazon EC2 OnDemand Instances behind an Application Load Balancer (ALB). The instances run across multiple Availability Zones.
The company wants to include the use of Spot Instances while continuing to use a small number of On-Demand Instances to ensure that the application remains highly available.
What is the MOST cost-effective solution that meets these requirements?
A. Add a Spot block resource to the AWS CloudFormation template. Use the diversified allocation strategy with step scaling behind the ALB.
B. Add a Spot block resource to the AWS CloudFormation template. Use the lowest-price allocation strategy with target tracking scaling behind the ALB.
C. Add a Spot Fleet resource to the AWS CloudFormation template. Use the capacity-optimized allocation strategy with step scaling behind the ALB.
D. Add a Spot Fleet resource to the AWS CloudFormation template. Use the diversified allocation strategy with scheduled scaling behind the ALB.
