You attempt to deploy host pools, application groups, and workspaces to a new subscription by using an ARM template. The deployment fails with an error stating that the resource type is not registered. Which resource provider must you register in the subscription to resolve the issue?

To deploy Azure Virtual Desktop (AVD) resources like host pools, application groups, and workspaces, the Microsoft.DesktopVirtualization resource provider must be registered in the Azure subscription. This provider enables Azure to understand and manage AVD-specific resources. The deployment failed because the subscription didn't recognize the resource types defined in your ARM template for AVD. Registering this provider grants the necessary permissions and capabilities. Microsoft.VirtualDesktop, Microsoft.RDS, and Microsoft.RemoteDesktop are not valid Azure resource provider names for Azure Virtual Desktop. Microsoft.RDS is related to traditional Remote Desktop Services, not AVD.