Which tool should you use?

You perform a Server Core Installation of Windows Server 2012 R2 on a server named Server1.
You need to add a graphical user interface (GUI) to Server1.
Which tool should you use?
A. the dism.exe command
B. the Add-WindowsFeature cmdlet
C. the imagex.exe command
D. the setup.exe command
E. the ocsetup.exe command
F. the Add-WindowsPackage cmdlet
G. the Install-Module cmdlet
H. the Install-RoleService cmdlet