The device shown operates based on a capacitive touch screen. This means that it utilizes an electric current to operate. Why will it operate with your finger but not a piece of plastic?
A) Your finger is a conductor but the plastic is not.
B) Your finger applies heat but the plastic does not.
C) You can apply more pressure with your finger than with the plastic.
D) The ridges of your fingerprints provide more surface area than the plastic.