问题：

[单选]

The client computers in your network run either Windows XP or Windows 7.  
All client computers are in a single Active Directory Domain Services （AD DS） organizational unit （OU） named MyClients. 
You install Windows Software Update Services （WSUS）.  
You create a Group Policy object （GPO） that enables automatic updates from the WSUS server， and you link the GPO to the MyClients OU.  
You place all client computers in a targeting group named MyClients.  
Testing reveals that a security update that is applicable to both Windows XP and Windows 7 causes a line-of-business application to fail on the Windows XP client computers.   
You need to ensure that the application runs on the Windows XP client computers and that the Windows 7 client computers receive the security update.  
What should you do？ （）

A .  Remove the Windows 7 client computers from the MyClients targeting group. Approve the update for installation to the All Computers targeting group.
B .  Remove the Windows XP client computers from the MyClients targeting group. Approve the update for installation to the All Computers targeting group.
C .  Remove the Windows 7 client computers from the MyClients targeting group. Approve the update for installation to the Unassigned Computers targeting group.
D .  Create a targeting group named MyXPClients beneath the MyClients targeting group.  Move the Windows XP client computers to the MyXpClients targeting group.  Approve the update for installation to the MyClients targeting group.