Correct Answer: ECitrix Workspace Environment Management (WEM) is specifically designed to optimize the performance of Citrix environments and manage user environments efficiently. It allows administrators to apply system and user-defined settings to control access to applications, including Regedit, command line, and PowerShell. While Citrix policies and ADMX templates can manage some aspects of user environment settings, they are not as comprehensive or straightforward for enforcing application restrictions as WEM. Therefore, to meet the requirement of disabling access to specific applications with minimal effort, WEM is the most suitable choice.