Answer : The correct option is, (C) 1st Law of Motion
Explanation :
First Law of Motion : An object at rest remains at rest and an object in motion remains in motion at the same speed and in the same direction unless an external force is applied to it and changes its state of motion.
Newtons first law of motion is also known as law of inertia.
For example : The motion of a kite when the wind changes.
Tightening of the seat belts in a car when it stops quickly.
In the demonstration, penny remains at rest when external force is applied then the penny falls into the cup.
Thus, the students' demonstration illustrate the 1st Law of Motion.