A. Create an AWS Step Functions workflow to check the state of the CloudWatch alarm. Configure the Step Functions workflow to exit with an error if the alarm is in the ALARM state. Create a new stage in the pipeline between each Region deployment stage. In each new stage, include an action to invoke the Step Functions workflow.
B. Configure an AWS CodeDeploy application to deploy a CloudFormation template with automatic rollback. Configure the CloudWatch alarm as the instance health check for the CodeDeploy application. Remove the CloudFormation actions from the pipeline. Create a CodeDeploy action in the pipeline stage for each Region.
C. Create a new pipeline stage for each Region where the application is deployed. Configure a CloudWatch alarm action for the new stage to check the state of the CloudWatch alarm and to exit with an error if the alarm is in the ALARM state
D. Configure the CloudWatch agent on the EC2 instances to report the application status to the Route 53 health check. Create a new pipeline stage for each Region where the application is deployed. Configure a CloudWatch alarm action to exit with an error if the CloudWatch alarm is in the ALARM state.