The correct answer is: C. adjustment switch.
The adjustment switch is the most likely culprit if the brightness or contrast adjustments are malfunctioning on a laptop. It is a small, usually plastic, switch that is used to control the brightness and contrast of the laptop’s display. If the adjustment switch is faulty, it can cause the display to be too bright or too dark, or it can cause the contrast to be too high or too low.
The fuse is a small, cylindrical device that is used to protect the laptop’s electrical system from damage. If the fuse is blown, it will need to be replaced. However, if the fuse is not blown, it is unlikely to be the cause of the problem.
The LED display is the screen that you see when you use your laptop. If the LED display is faulty, it will need to be replaced. However, if the LED display is working properly, it is unlikely to be the cause of the problem.
The LED display cable is the cable that connects the LED display to the laptop’s motherboard. If the LED display cable is faulty, it will need to be replaced. However, if the LED display cable is working properly, it is unlikely to be the cause of the problem.
Therefore, the most likely cause of the problem is the adjustment switch.