You need to start the computer and install the image that is stored on the WDS server.

You install the Windows Deployment Services (WDS) role on a server that runs Windows Server 2008
R2. You plan to install Windows 7 on a computer that does not support Preboot Execution
Environment (PXE). You have a Windows 7 image that is stored on the WDS server. You need to start
the computer and install the image that is stored on the WDS server.

A.
a capture image

B.
a CD-ROM that contains PXE drivers

C.
a discover image

D.
an install image

Explanation:
To start the computer and install Windows Vista image stored on the WDS server, you should create
the Discover image. If you have a computer that is not PXE enabled, you can create a discover image
and use it to install an operating system on that computer. When you create a discover image and

save it to media (CD, DVD, USB drive, and so on), you can then boot a computer to the media. The
discover image on the media locates a Windows Deployment Services server, and the server deploys
the install image to the computer. You can configure discover images to target a specific Windows
Deployment Services server. This means that if you have multiple servers in your environment, you
can create a discover image for each, and then name them based on the name of the server.
Reference: http://technet2.microsoft.com/WindowsVista/en/library/9e197135-6711-4c20- bfadfc80fc2151301033.mspx?mfr=true