A Company Has Many Projects That Run in Multiple AWS

A company has many projects that run in multiple AWS Regions. The projects usually have a three-tier architecture with Amazon EC2 instances that run behind an Application Load Balancer. The instances run in an Auto Scaling group and share Amazon Elastic File System (Amazon EFS) storage and Amazon RDS databases. Some projects have resources in more than one Region. A solutions architect needs to identify each project's individual costs. Which solution will provide this information with the LEAST amount of operational effort?

A) Use Cost Explorer to perform one-time queries for each Region and create a report that filters by project.
B) Use the AWS Billing and Cost Management details page to see the actual usage costs of the resources by project.
C) Use AWS Systems Manager to group resources by project and monitor each project's resources and cost.
D) Use AWS Billing and Cost Management to activate cost allocation tags and create reports that are based on the project tags.