You connect your computer to a multimedia projector. When you play a video， you cannot hear the audio. You need to ensure that the projector provides audio and video playback. What should you do？（）

A. Configure the computer to use the default sound scheme.
B. Enable the Presentation Settings option. Adjust the volume settings as appropriate.
C. In the Line In Properties dialog box， clear the Allow applications to take exclusive control of this device check box.
D. In the Presentation settings dialog box， select the I always give a presentation when I use this display configuration check box.