问题：

[单选]

You are the network administrator for The network consists of a single Active Directory domain named All servers run Windows Server 2003. All client computers run Windows 2000 Professional with Service Pack 4 or Windows XP Professional.
You install Software Update Services (SUS) on a computer named TestKing1. You create a GPO that configures all client computers to receive their software update from TestKing1.
One week later, you run Microsoft Baseline Security Analyzer (MBSA) on all client computers to find out whether all updates are being applied. You discover that all the Windows 2000 Professional client computer received updates, but the Windows XP Professional client computers do not receive updates.
You verify that the GPO setting was applied on all Windows XP Professional computers.
You need to ensure that the Windows XP Professional client computers receive their updates from TestKing1.
What should you do?（）

A . Make all users of the Windows XP Professional client computers members of the Administrators local group.
B . On all Windows XP Professional client computers, install Service Pack 1.
C . On all Windows XP Professional client computers, restart Automatic Updates.
D . On all Windows XP Professional client computers, delete the NoAutoUpdate value under HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU.