When installing a new Plug and Play sound card， a technician should turn off and unplug the computer； remove the computer’s cover； locate the sound card slot， insert and secure the card in the slot and：（）

• A、plug in and turn on the computer； let Windows recognize the new hardware and install the driver.
• B、plug in the computer； let Windows recognize the new hardware and plug in the speakers.
• C、let Windows recognize the new hardware； install the driver and plug in the speakers.
• D、turn on and plug in the computer； let Windows recognize the new hardware and install the driver.