According to the HDX Insight documentation, HDX Insight is the integration of NetScaler Network Inspector and Performance Manager with Director. It captures data about ICA traffic and provides a dashboard view of real time and historical details. To monitor NetScaler appliances deployed in this mode, first add the NetScaler appliance to the NetScaler Application Delivery Management (ADM) inventory, enable AppFlow, and then view the reports on the dashboard. External users who access Citrix Virtual App and Desktop applications must authenticate themselves on the NetScaler Gateway. Therefore, the three components that the administrator will need to review are:
* Citrix Application Delivery Management: This is the platform that collects and analyzes the AppFlow records generated by the NetScaler appliance.
* Citrix Gateway: This is the component that provides secure access to the Citrix Virtual App and Desktop applications and generates the AppFlow records for HDX Insight.
* Citrix Director: This is the web-based tool that displays the HDX Insight reports and allows the administrator to troubleshoot performance issues.

Citrix Virtual Apps and Desktops support several high availability solutions for on-premises deployments, including Always On Availability Groups, SQL Server database mirroring, and SQL clustering. These features ensure automatic failover and continuous operation1

Process Explorer is a tool that can be used to get further details on orphaned processes in the session.
According to the Citrix Virtual Apps and Desktops 7 Deployment and Administration course, Process Explorer can be used to "identify processes that are preventing a session from logging off" (Module 6:
Troubleshooting User Connection Issues, Lesson: Troubleshooting Session Logon and Logoff Issues, Slide
8). Additionally, according to the Citrix Virtual Apps and Desktops 7 Administration Exam Guide, one of the objectives is to "use Process Explorer to identify orphaned processes" (Objective 6.3: Troubleshoot Session Logon and Logoff Issues). Therefore, Process Explorer is the correct answer.

Application Lingering allows applications to stay open for a configurable amount of time after a user closes them, which can reduce application launch times in subsequent sessions.

Folder redirection is a feature of Microsoft Windows and can be used with Profile Management. It allows folders, such as Application Data or Documents, to be saved (redirected) to a network location. The contents of the folders are stored in the redirected location and not included within the user profile, which therefore reduces in size. This can improve the logon times for users with large Documents folders1
1: Plan folder redirection with Profile Management