How can you prevent developers from attaching an Elastic IP to production EC2 instances and ensure the security team is alerted if any production instance has an Elastic IP at any time?

The correct option provides a robust, multi-layered solution. First, attaching an IAM policy that explicitly denies ec2:AssociateAddress permissions to developer IAM groups is a preventative measure, stopping developers from attaching Elastic IPs in the first place. Second, creating a custom AWS Config rule that specifically checks for Elastic IPs on instances tagged as "production" provides continuous auditing and detection. If an Elastic IP is found (perhaps due to a misconfiguration or an action by an authorized user), AWS Config will flag it as non-compliant and can trigger alerts to the security team, ensuring immediate notification. The other options are less effective: Querying CloudTrail logs with Athena is reactive and might have a delay in detection, and disassociating an Elastic IP via Lambda after it's been attached is a remediation step, not a prevention. Scheduling a Lambda function to periodically check is also reactive and might have a detection delay, similar to the Athena approach, and doesn't prevent the initial attachment. Verifying EC2 IAM roles deny associate-address permissions is incorrect because EC2 instance roles define permissions for the instance itself, not for users interacting with the instance. Users' IAM policies control their ability to attach Elastic IPs.