You are the desktop administrator for one of your company's branch offices. The network in the branch office consists of a single network segment, which contains a domain controller, a DHCP server, 10 Windows 2000 Server computers, and 50 Windows 2000 Professional computers. All servers and client computers are members of the company's Active Directory domain. You purchase 50 new client computers for the branch office. Each new client computer contains a built-in PXE-compliant network adapter. You install and configure RIS on one of the Windows 2000 Server computers that is on the network in the branch office. You create a Windows XP Professional RIS image on the Windows 2000 Server computer. You connect the new client computers to the network in the office, and you turn on each computer. Each computer displays a message stating that it cannot contact a PXE boot server. You verify that the RIS server is connected to the network. You need to ensure that the new client computers can connect to the RIS server and can begin installing Windows XP Professional. What should you do?（）

• A、Ask a domain administrator to authorize the RIS server. 
• B、Grant the Everyone group Allow - Read NTFS permission on the RIS image.
• C、Install RIS on the domain controller. Copy the RIS image to the domain controller.
• D、Add a reservation for the RIS server to the DHCP server.