You need to configure the power settings of your portable computer so that the display turns off when it is inactive and running on battery power. You also need to ensure that the power settings of the hard disk remain unaffected.  What should you do？（）

• A、Change the advanced power settings of the Balanced power plan.
• B、Configure the portable computer to use the Power saver power plan.
• C、Configure the portable computer to use the High performance power plan.
• D、Restore the Power Saver power plan to the default settings.