Which combination of actions will meet these requirements?

Explanations:

Activating user-defined cost allocation tags allows the company to track costs associated with specific applications and teams. These tags can be customized to reflect the team’s structure and application ownership, providing detailed visibility into costs on the monthly bill.

AWS-generated cost allocation tags do not specifically reflect the ownership of applications or teams. While they provide some level of cost categorization, they are not tailored to the company’s specific applications and teams, which limits their effectiveness for detailed cost reporting.

Creating cost categories in Billing and Cost Management enables the company to group costs based on applications. This categorization aids in generating reports that reflect the financial performance of each application, making it easier to analyze costs over time.

While IAM access to Billing and Cost Management is important for security and permissions, it does not directly contribute to cost tracking or reporting. It is a necessary setup for team members to access billing data but does not fulfill the reporting requirements directly.

Creating a cost budget is useful for managing spending but does not provide the detailed cost allocation or reporting capabilities required to attribute costs to specific applications or teams. Budgets can help with forecasting but are not a direct means of generating reports for past costs.

Enabling Cost Explorer allows the company to visualize and analyze spending patterns over time. It supports reporting for the last 12 months and aids in forecasting costs for the next 12 months, fulfilling the requirement for comprehensive cost analysis.