A developer must store application configuration values that expire at a certain date and time and receive notifications before they expire. Which approach provides this functionality with the least operational overhead?

The correct answer is to create an advanced Systems Manager Parameter Store parameter and set Expiration and ExpirationNotification policy types. Advanced parameters in AWS Systems Manager Parameter Store support parameter policies, including Expiration and ExpirationNotification. The Expiration policy automatically deletes a parameter after a specified date and time, while the ExpirationNotification policy sends an Amazon SNS notification before the parameter expires. This built-in functionality directly addresses the requirements with the least operational overhead. Standard Systems Manager Parameter Store parameters do not support parameter policies, making the first two options incorrect as they would require custom solutions (like a Lambda function) to achieve expiration and notifications, increasing operational overhead. Running a cron job on an EC2 instance also introduces significant operational overhead compared to using native Parameter Store policies.