[Reference: AWS documentation on CloudFormation StackSets., This corresponds to Option A: Use AWS CloudFormation StackSets to deploy the CloudFormation stacks in all AWS accounts.,  Step 2: Isolate EC2 Instances using Lambda and Security GroupsWhen an EC2 instance is compromised, it needs to be isolated from the network. This can be done by creating a security group with no inbound or outbound rules and attaching it to the instance. A Lambda function can handle this process and can be triggered automatically by an Amazon EventBridge rule when a specific tag (e.g., "isolation") is applied to the compromised instance., Action: Create a Lambda function that attaches an isolated security group (with no inbound or outbound rules) to the compromised EC2 instances. Set up an EventBridge rule to trigger the Lambda function when the "isolation" tag is applied to the instance., Why: This automates the isolation process, ensuring that any compromised instances are immediately cut off from the network, reducing the potential damage from the compromise., Reference: AWS documentation on Tag-based Event Handling., This corresponds to Option E: Create an AWS CloudFormation template that creates an EC2 instance role that has no IAM policies attached. Configure the template to have a security group that has no inbound rules or outbound rules. Use the CloudFormation template to create an AWS Lambda function that attaches the IAM role to instances. Configure the Lambda function to replace any existing security groups with the new security group. Set up an Amazon EventBridge rule to invoke the Lambda function when a specific tag is applied to a compromised EC2 instance., , , ]