AWS Certified Solutions Architect – Professional — Question 789

A company uses AWS Organizations to manage its AWS accounts. The company needs a list of all its Amazon EC2 instances that have underutilized CPU or memory usage. The company also needs recommendations for how to downsize these underutilized instances.

Which solution will meet these requirements with the LEAST effort?

Answer options

• A. Install a CPU and memory monitoring tool from AWS Marketplace on all the EC2 instances. Store the findings in Amazon S3. Implement a Python script to identify underutilized instances. Reference EC2 instance pricing information for recommendations about downsizing options.
• B. Install the Amazon CloudWatch agent on all the EC2 instances by using AWS Systems Manager. Retrieve the resource optimization recommendations from AWS Cost Explorer in the organization's management account. Use the recommendations to downsize underutilized instances in all accounts of the organization.
• C. Install the Amazon CloudWatch agent on all the EC2 instances by using AWS Systems Manager. Retrieve the resource optimization recommendations from AWS Cost Explorer in each account of the organization. Use the recommendations to downsize underutilized instances in all accounts of the organization.
• D. Install the Amazon CloudWatch agent on all the EC2 instances by using AWS Systems Manager. Create an AWS Lambda function to extract CPU and memory usage from all the EC2 instances. Store the findings as files in Amazon S3. Use Amazon Athena to find underutilized instances. Reference EC2 instance pricing information for recommendations about downsizing options.

Correct answer: B

Explanation

AWS Cost Explorer natively generates resource optimization recommendations, including memory-based recommendations if the Amazon CloudWatch agent is installed to gather memory metrics. Accessing these recommendations from the AWS Organizations management account consolidates findings across all member accounts in a single place, which requires much less effort than logging into each individual account (Option C). Options A and D are incorrect because they require building custom scripts, databases, or queries, which drastically increases operational overhead.