Which Azure tool should the finance department use to gain visibility into cloud costs and to create budgets and spending thresholds?

Azure Cost Management is the correct tool because it provides robust capabilities for tracking, analyzing, and optimizing cloud spending across Azure and other clouds. It allows users to create budgets, set spending thresholds, and receive alerts when costs exceed defined limits, which is crucial for financial oversight. Azure Monitor focuses on collecting and analyzing telemetry data for performance and availability, not cost management. Azure Lighthouse enables multi-tenant management for service providers, which is unrelated to internal cost tracking. Azure Automation is used for automating tasks and processes, not for cost visibility or budgeting.