Your network contains a windows Server 2016 R2 image named Server12.wim.Server12.wim contains the images shown in the following table.

You need to enable the Windows Server Migration Tools feature in the windows Server 2016 R2 Datacenter image.
You want to achieve this goal by using the minimum amount of administrative effort.
Which command should you run first?

A.

B.
dism.exe /mount-wim /wimfile:c:\\Server12.wim /index:4 /mountdir:c:\\mount

C.
imagex.exe /capture c: c:\\Server12.wim “windows Server 2016 r2 datacenter”

D.
imagex.exe /apply c:\\Server12.wim 4 c:\\

Explanation:
This command will mount the image before making any changes.

http://technet.microsoft.com/en-us/library/cc749447(v=ws.10).aspx
http://technet.microsoft.com/en-us/library/dd744382(v=ws.10).aspx