Configure an Amazon EventBridge rule for AWS Health EC2 retirement scheduled events that invokes an AWS Systems Manager Automation runbook to stop and then start the impacted instances is correct because AWS publishes scheduled instance retirement notifications via AWS Health and an EventBridge rule can capture that notification and invoke an SSM Automation runbook to perform the required stop and start so the instance is moved to healthy hardware before the retirement takes effect.

The AWS Health signal such as AWS_EC2_INSTANCE_RETIREMENT_SCHEDULED is the precise indicator of a scheduled retirement and EventBridge can route that event to Systems Manager. Systems Manager Automation can target the affected instance ids and perform an orderly stop and start with the necessary IAM permissions and logging, and this approach reliably acts only when a retirement is scheduled.

Attach the instances to an Auto Scaling group with Elastic Load Balancing health checks and rely on automatic replacement if a host degrades is unsuitable because ASG and ELB react to runtime health failures rather than AWS-scheduled retirements and they may replace instances instead of stopping and starting the same instance as required.

Create an Amazon EventBridge rule using Amazon EC2 as the source that matches instance state changes to stopping or shutting-down and trigger an AWS Systems Manager Automation document to start the instances is too broad because EC2 state change events indicate that a stop has already occurred and they do not convey AWS-scheduled retirement notifications and this would trigger on routine operational stops and cause unintended restarts.

Enable EC2 Auto Recovery by creating a CloudWatch alarm with the Recover action and schedule recovery to occur after hours is incorrect because Auto Recovery responds to system status check failures rather than scheduled retirements and CloudWatch recover actions cannot be used to perform the required stop and start to migrate an instance off retired hardware.

Full AWS Practitioner Certification Question