Which solution will meet this requirement in the MOST operationally efficient way?

Activate the eip-attached AWS Config managed rule to run automatically when resource changes occur in the AWS account. Configure automatic remediation for the rule. Specify the AWS-ReleaseElasticIP AWS Systems Manager Automation runbook for remediation. Specify an appropriate role that has permission for the remediation.

Create a custom Lambda function that calls the EC2 ReleaseAddress API operation and specifies the Elastic IP address AllocationId. Invoke the Lambda function by using an Amazon EventBridge rule. Specify AWS services as the event source, All Events as the event type, and AWS Trusted Advisor as the target.

Create an Amazon EventBridge rule. Specify AWS services as the event source, Instance State-change Notification as the event type, and Amazon EC2 as the service. Invoke a Lambda function that extracts the Elastic IP address from the notification. Use AWS CloudFormation to release the address by specifying the AllocationId as an input parameter.

Create a custom Lambda function that calls the EC2 ReleaseAddress API operation and specifies the Elastic IP address AllocationId. Invoke the Lambda function by using an Amazon EventBridge rule. Specify AWS services as the event source, Instance State-change Notification as the event type, and Amazon EC2 as the service.