You are the desktop administrator for your company. You install Windows XP Professional on your portable computer. The computer is configured to use an IEEE 1394 PC card. You use the computer to download pictures from a digital camera while you are at the office. You attend a meeting every Monday. During the meeting you use a battery to supply power to your portable computer. Occasionally, the battery runs out of power during these meetings. You need to configure the computer to conserve battery power while you attend your weekly meeting without affecting your power options when you use the computer at your office. How should you configure your computer?（） 

• A、Use Device Manager to disable the IEEE 1394 PC card power device. 
• B、In Control Panel, select the Minimal Power Management power scheme in the Power Options Properties. 
• C、Create an additional hardware profile, and disable the IEEE 1394 PC card for this profile. 
• D、Use Device Manager to configure the IEEE 1394 PC card Host Controller power management scheme. Select the Allow this device to bring the computer out of standby check box.