A company is running distributed computing software to manage a fleet of 20 Amazon EC2 instances for calculations. The fleet includes 2 control nodes and 18 tas...

A company is running distributed computing software to manage a fleet of 20 Amazon EC2 instances for calculations. The fleet includes 2 control nodes and 18 task nodes to run the calculations. Control nodes can automatically start the task nodes.
Currently, all the nodes run on demand. The control nodes must be available 24 hours a day, 7 days a week. The task nodes run for 4 hours each day. A SysOps administrator needs to optimize the cost of this solution.
Which combination of actions will meet these requirements? (Choose two.)

A. Purchase EC2 Instance Savings Plans for the control nodes. B. Use Dedicated Hosts for the control nodes. C. Use Reserved Instances for the task nodes. D. Use Spot Instances for the control nodes. Use On-Demand Instances if there is no Spot availability. E. Use Spot Instances for the task nodes. Use On-Demand Instances if there is no Spot availability.