Which tool lets a developer quickly locate all VMs without tags across subscriptions for cleanup?

Azure Resource Graph is the correct choice because it provides an efficient, cross-subscription way to query Azure resources at scale. You can write a Kusto Query Language (KQL) query to find all Virtual Machines (VMs) that do not have specific tags, or any tags at all, across multiple subscriptions. This makes it ideal for inventory, asset management, and identifying resources for cleanup. Azure Policy is used for enforcing organizational standards and assessing compliance, not for ad-hoc querying of existing resources for cleanup. Azure Advisor provides recommendations for optimizing cost, performance, reliability, operational excellence, and security, but it doesn't offer the granular querying capability needed to find untagged resources directly. Azure Monitor collects and analyzes telemetry data from Azure resources, focusing on performance, availability, and operational health, not resource inventory or tag management.