What would be a reliable and efficient way to handle the cleanup of Amazon EC2 resources with your configuration management systems?

When an Auto Scaling group is running in Amazon Elastic Compute Cloud (EC2), your application rapidly scales up and down in response to load within a 10-minutes window; however, after the load peaks, you begin to see problems in your configuration management system where previously terminated Amazon EC2 resources are still showing as active.

What would be a reliable and efficient way to handle the cleanup of Amazon EC2 resources with your configuration management systems? Choose 2 answers
A . Write a script that is run by a daily cron job on an Amazon EC2 instance and that executes API Describe calls of the EC2 Auto Scaling group and removes terminated instances from the configuration management system
B . Configure an Amazon Simple Queue Service (SQS) queue for Auto Scaling actions that has a script that listens for new messages and removes terminated instances from the configuration management system
C . Use your existing configuration management system to control the launching and bootstrapping of instances to reduce the number of moving parts in the automation
D . Write a small script that is run during Amazon EC2 instance shutdown to de-register the resource from the configuration management system
E . Use Amazon Simple Workflow Service (SWF) to maintain an Amazon DynamoDB database that contains a whitelist of instances that have been previously launched, and allow the Amazon SWF worker to remove information from the configuration management system

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Answer: A,D