Your network contains an Active Directory domain named contoso.com.
All servers run Windows Server 2008 R2.
A server named Server1 has the Windows Deployment Services (WDS) server role installed.
A custom Windows 7 image is available for download from Server1.
A server named Server2 has the Hyper-V server role installed.
You create a virtual machine (VM) named VM1 on Server2.
You need to deploy the Windows 7 image from Server1 to VM1.
What should you do first?

A.
On Server1, configure a multicast transmission.

B.
On Server1, adjust the PXE Response Delay setting.

C.
From the properties of VM1, install a legacy network adapter.

D.
From the properties of VM1, install a synthetic network adapter.

Explanation:
Networking and virtual machines
In Hyper-V, when a virtual machine is created and attached to a virtual network, it connects using a virtual network adapter. There are two types of network adapters available for Hyper-V: a network adapter and a legacy network adapter. For the network adapter to work, integration services must be installed, which is part of the Hyper-V installation. If integration services cannot be installed because of the version of the operating system, the network adapter cannot be used. Instead, you need to add a legacy network adapter that emulates an Intel 21140-based PCI Fast Ethernet Adapter and works without installing a virtual machine driver. A legacy network adapter also supports network-based installations because it includes the ability to boot to the Pre-Boot Execution Environment (PXE). The legacy network adapter is also required if a virtual machine needs to boot from a network. You will need to disable the network adapter after the PXE boot.
Source: http://technet.microsoft.com/nl-nl/library/cc816585(WS.10).aspx