A company is running an application on a fleet of Amazon EC2 instances behind an Application Load Balancer (ALB). The EC2 instances are launched by an Auto Scaling group and are automatically registered in a target group. A SysOps administrator must set up a notification to alert application owners when targets fail health checks.
What should the SysOps administrator do to meet these requirements?
A. Create an Amazon CloudWatch alarm on the UnHealthyHostCount metric. Configure an action to send an Amazon Simple Notification Service (Amazon SNS) notification when the metric is greater than 0.
B. Configure an Amazon EC2 Auto Scaling custom lifecycle action to send an Amazon Simple Notification Service (Amazon SNS) notification when an instance is in the Pending: Wait state.
C. Update the Auto Scaling group. Configure an activity notification to send an Amazon Simple Notification Service (Amazon SNS) notification for the Unhealthy event type.
D. Update the ALB health check to send an Amazon Simple Notification Service (Amazon SNS) notification when an instance is unhealthy.
