You are the network administrator for The network consists of a single Active Directory domain named All servers run Windows Server 2003. A server named TestKing2 functions as an application server. Users in the TestKing marketing department use an application on TestKing2 to analyze data. The application produces a high volume of disk activity. You give access to 15 new users for the application on TestKing2. Users in the TestKing marketing department report unacceptable delays when they use the application during periods of peak activity. You use System Monitor to analyze the performance of TestKing2. You need to ensure that TestKing2 can support the new users. Which counter should you monitor?（）

A. The % Disk Time counter for the PhysicalDisk performance object
B. The Current Disk Queue Length counter for the PhysicalDisk performance object
C. The Free Megabytes counter for the LogicalDisk performance object
D. The Disk Transfers/sec counter for the LogicalDisk performance object