A company uses AWS Organizations with Consolidated Billing. They want to allocate costs to different business units based on resource usage. Some resources, like shared network infrastructure, cannot be directly tagged to a single business unit. How can they achieve accurate cost allocation?

Use AWS Cost Categories to group accounts and tags, and define split charge rules for shared resources.

Create a custom AWS Lambda function to parse the Cost and Usage Report (CUR) and manually calculate splits.

Use AWS Budgets to set limits for each business unit and alert when shared resources exceed limits.

Apply multiple business unit tags to the shared resources and use Cost Explorer to filter.