The built-in Virtual Machine Contributor role provides the ability to manage virtual machines in Azure, not their networking components or storage accounts, nor does it allow the user to create or delete virtual machines. This alignment with the requirement makes it the best choice. The Virtual Machine User Login role only allows a user to log into a virtual machine. The Owner role provides full access, including creating and deleting virtual machines, which exceeds the required permissions. The Reader role grants read-only access and would not permit the user to start or restart virtual machines.