You have a server named Server1 that has a Server Core installation of Windows Server 2008 R2.
Server1 has the DHCP Server server role and the File Server server role installed.You need to upgrade
Server1 to Windows Server 8 with the graphical userinterface (GUI).
The solution must meet the following requirements:
Preserve the server roles and their configurations.
Minimize Administrative effort.
What should you do?

A.
On Server1, run setup.exe from the Windows Server8 installation media and select Server with a GUI.

B.
Start Server1 from the Windows Server 8 installation media and select Server Core Installation. Whenthe
installation is complete, add the Server Graphical Shell feature.

C.
Start Server1 from the Windows Server 8 installation media and select Server with a GUI.

D.
On Server1, run setup.exe from the Windows Server8 installation media and select Server Core
Installation. When the installation is complete, add the Server Graphical Shell feature.

Explanation:
A: Server is on 2008 R2 core, must install 2012 core and then GUI B: Not least effort
C: Not least effort
D: Upgrade to 2012 and install GUI shell
http://technet.microsoft.com/en-us/library/jj574204.aspx Upgrades that switch from a Server Core installation to
the Server with a GUI mode of Windows Server 2012 in one step (and vice versa) are not supported. However,
after upgrade is complete, Windows Server 2012 allows you to switch freely between Server Core and Server
with a GUI modes. For more information about these installation options, how to convert between them, and
how to use the new Minimal Server Interface and Features on Demand, see http://technet.microsoft.com/
library/hh831786.