You are the network administrator for your company. A user reports that the USB ports on his Windows 2000 Professional portable computer function only when the portable computer is in its docked position at the office. He asks you to configure the computer so that the USB port works when the portable computer is docked and when it is undocked and running on battery power. You verify that the portable computer supports ACPI power management. What should you do？（）

A.Modify the portable computer’s power management settings to ensure the USB ports are not  shut down when the computer is running on battery power.

B.Modify the portable computer’s BIOS settings to disable ACPI when the computer is running  on battery power.

C.Modify the portable computer’s undocked hardware profile, and enable the USB root hub.

D.Disable the BIOS power management features in the portable computer’s BIOS settings.

E.Obtain external power supplies for the user’s USB devices. Ensure that these power supplies  are connected when the portable computer is undocked.

F.Undock the portable computer, and reinstall the drivers for the USB port.