You are trying to connect an external LCD projector to your laptop, but when you connect the video cable nothing seems to happen. Which of these would be the best next step?
A) Press the toggle key to enable the external monitor
B) Reboot your laptop, login again, and then connect the cable
C) Close the laptop display before connecting the cable
D) Turn the LCD display off, connect the cable, and turn the LCD display on again
E) Quickly change your presentation to discuss the nocturnal habits of the African bushbaby. Wikipedia is your friend.