Which governance tool enforces a maximum VM size of Standard_D2s_v3 within a resource group?

Azure Policy is the correct answer because it allows you to create, assign, and manage policies that enforce rules and effects over your resources to stay compliant with corporate standards and service level agreements. In this scenario, you would define a policy that restricts the VM SKUs allowed within a specific resource group, enforcing the maximum size of StandardD2sv3. Azure Blueprints define a repeatable set of Azure resources that implement and adhere to standards, patterns, and requirements, but they don't actively enforce ongoing compliance like Policy does. Azure Monitor collects and analyzes telemetry data from your Azure and on-premises environments, focusing on performance and availability, not resource governance. Azure Resource Graph provides efficient resource exploration with the ability to query across multiple subscriptions, but it's a query service, not an enforcement mechanism.