Option 3: OLED panel
is the correct answer.
Explanation:
OLED stands for Organic Light Emitting Diode.It is a type of LED having a film o organic compound that is emissive electroluminescent layer.This film emits light when electric current is given to it. OLED is used in touchscreens in mobiles and other devices so that they respond when pressure is applied to the surface.I hope it will help you!