AWS Certified Solutions Architect Professional SAP-C02 Practice Question

The correct answer is to use AWS Trusted Advisor with its organizational view. AWS Trusted Advisor is specifically designed to provide best-practice recommendations across several categories, including cost optimization. It has pre-built checks that identify specific unused or idle resources, such as 'Unassociated Elastic IP Addresses', 'Amazon RDS Idle DB Instances', and 'Idle Load Balancers'. The organizational view feature allows these checks to be aggregated across all accounts in an AWS Organization, providing the required centralized report with minimal manual effort.

• Using AWS Cost Explorer is incorrect because, while it provides rightsizing recommendations for underutilized EC2 and EBS resources, it does not have the same breadth of direct checks for other orphaned resources like unassociated EIPs and idle load balancers. It is more focused on optimizing active resources rather than identifying all types of unused ones.
• Using AWS Compute Optimizer is incorrect because its primary function is to recommend optimal configurations for active workloads, such as EC2 instances, Auto Scaling groups, and EBS volumes, to improve performance and reduce cost. It is not designed to identify completely unused or orphaned resources like unassociated EIPs or idle load balancers.
• Using AWS Cost and Usage Reports (CUR) with Amazon Athena is incorrect because it is not the most effective or least effort-intensive solution for this specific task. While it's a powerful and flexible approach for deep cost analysis, it requires significant manual effort to set up the data pipeline and, more importantly, to write and maintain complex SQL queries to define and identify what constitutes an 'idle' or 'unattached' resource from raw billing data. This is far more complex than using the pre-built checks provided by Trusted Advisor.