Explanation
According to the Citrix Virtual Apps and Desktops 7 Advanced Administration guide1, the administrator can use custom access in Citrix Cloud to grant the contractor access to specific services and features, such as the Citrix Virtual Apps and Desktops Service. The administrator can also use the Delivery Group Administrator role in the Citrix Virtual Apps and Desktops Service to allow the contractor to deliver applications, desktops, and machines, and manage the associated sessions. This role has the minimum permissions required to administer the inventory application. The other roles are either too broad or too restrictive for the scenario.