HOTSPOT
You have a server named Server1 that runs Windows Server 2012 R2.
You need to switch Server1 to a Server Core installation of Windows Server 2012 R2.
What command should you run?
To answer, select the appropriate options in the answer area.
Answer: 
To get a CORE from a GUI you need:
Uninstall-WindowsFeature Server-Gui-Shell, Server-Gui-Mgmt-Infra
Can anyone tell why the answer is just:
Uninstall-WindowsFeature Server-Gui-Mgmt-Infra ?
Please
Because you don’t.
Server-Gui-Mgmt-Infra gets you to Server Core.
https://blogs.technet.microsoft.com/bruce_adamczak/2013/02/06/windows-2012-core-survival-guide-changing-the-gui-type/