You are the network administrator for The network contains a Windows Server 2003 compter named TestKing1. TestKing1 functions as a file server. Six users in the accounting department use an accounting software application to open files that are stored in a shared folder on TestKing1. The users keep these files open for an extended period of time. You need to restart TestKing1. You need to find out if any files on Testking1 are open before you restart the computer. What should you do?（）

A. Use Computer Management to view existing connections.
B. Use the netsend command to send a message to all domain members.
C. Use Task Manager to monitor processes started by all users.
D. Use System Monitor to monitor the Server object in Report view.