A. Implement a cron job on each EC2 instance to run once every 60 minutes and calculate the current CPU utilization. Initiate an instance shutdown if CPU utilization is less than 10%.
B. Implement an Amazon CloudWatch alarm for each EC2 instance to monitor average CPU utilization. Set the period at 1 hour, and set the threshold at 10%. Configure an EC2 action on the alarm to stop the instance.
C. Install the unified Amazon CloudWatch agent on each EC2 instance, and enable the Basic level predefined metric set. Log CPU utilization every 60 minutes, and initiate an instance shutdown if CPU utilization is less than 10%.
D. Use AWS Systems Manager Run Command to get CPU utilization from each EC2 instance every 60 minutes. Initiate an instance shutdown if CPU utilization is less than 10%.