A user states that they are trying to project their laptop to a screen for a presentation. They have plugged the projector cable into their laptop, and turned the projector on, but no signal is found. Which of the following should the technician perform FIRST?（）

• A、Ensure the projector is receiving power
• B、Verify the laptop is not running on battery
• C、Toggle the function key for displays
• D、Replace the projector cable with another