A financial firm must restrict VM deployments to a single Azure region to meet regulatory requirements. Which service should they use?

Azure Policy is the correct choice because it allows you to define and enforce organizational standards and assess compliance at scale. You can create a policy definition that restricts resource deployments, such as Virtual Machines, to specific Azure regions. If a user attempts to deploy a VM outside the allowed region, Azure Policy will block the deployment, ensuring regulatory compliance. Azure Blueprints are used for deploying and updating entire environments, but they don't primarily focus on enforcing ongoing compliance rules like region restrictions. Azure Monitor is for collecting, analyzing, and acting on telemetry data from your Azure and on-premises environments, not for enforcing deployment constraints. Azure Resource Locks prevent accidental deletion or modification of resources, but they don't control where resources can be deployed.