You manage a software update infrastructure by using Windows Server Update Services (WSUS) 3.0. All client computers run Windows XP Professional Service Pack 3 (SP3). The client computers receive Automatic Updates from the WSUS server, and they are configured to install Automatic Updates immediately. From the Update Services console, you approve a required security update for all client computers. You need to force a client computer to apply the required security update as soon as possible. Which tool should you use? （）

A. Secedit
B. Wuauclt
C. Wsusutil
D. Gpupdate