A. Create an Amazon CloudWatch alarm based on the CPUUtilization metric. When the metric is 0% for 24 hours, trigger an action to terminate the EC2 instance when the alarm is triggered.
B. Create an AWS Lambda function to check all EC2 instances and terminate instances running more than 24 hours. Trigger the function with an Amazon CloudWatch Events event every 15 minutes.
C. Add an action to AWS Trusted Advisor to turn off EC2 instances based on the Low Utilization Amazon EC2 Instances check, terminating instances identified by Trusted Advisor as running for more than 24 hours.
D. Install the unified Amazon CloudWatch agent on every EC2 instance. Configure the agent to terminate instances after they have been running for 24 hours.