Managing AWS Costs: Keeping Track of Budget and Receiving Notifications

Correct Answer: B.

This is given in the AWS Documentation.

You can monitor your estimated AWS charges using Amazon CloudWatch.

When you enable the monitoring of estimated charges for your AWS account, the estimated charges are calculated and sent several times daily to CloudWatch as metric data.

Option A is invalid because you cannot get cost as a metric specifically in Cloudwatch.

Options C and D are invalid because the billing alarm needs to be created from Cloudwatch.

For more information on monitoring charges with AWS Cloudwatch, please refer to the below URL-

https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/monitor_estimated_charges_with_cloudwatch.htm

The most appropriate solution to achieve the requirement of being notified when approaching the budget limit for AWS resource usage costs is to create a billing alarm. Billing alarms can monitor and alert on your AWS usage and costs, and can be set up to notify you when your AWS charges reach certain thresholds.

Out of the given options, the most appropriate answer is B. Create a billing alarm from within Cloudwatch.

Here's how you can create a billing alarm from within CloudWatch:

1. Open the CloudWatch console.
2. In the navigation pane, choose "Alarms", and then choose "Create alarm".
3. Choose "Select metric", and then choose "Billing" from the list of available metrics.
4. Choose "Total Estimated Charge" or "Estimated Charges" (depending on your preference), and then choose "Next".
5. Configure your alarm by setting the threshold you want to be alerted on, and choose the actions to be taken when the threshold is reached.
6. Review the alarm configuration, and choose "Create alarm".

Once the billing alarm is created, you can receive notifications via email or SMS when the threshold is reached or exceeded.

Note: Cost Explorer is a service that provides comprehensive cost management capabilities, but it is not the most appropriate solution for this requirement. IAM is a service for managing access to AWS resources, and it is not relevant to this requirement. Option A is not incorrect, but it is not the most appropriate solution. A collection of resources can be used as a metric for an alarm, but in this case, it is more appropriate to use billing metrics.