If the slight resistance you feel from a light switch (when you flick it) is the reaction force, what is the action force?

A. flicking the switch

B. the light turning on

C. friction between your finger and the switch

D. the switch moving from the "off" to the "on" position

You pull hard on both ends of a thick spring, but it does not stretch. Is there an action force and, if so, what is it?

A. No, there is no action force.

B. Yes, the action force is the spring resisting being pulled on.

C. Yes, the action force is the pulling on both ends of the spring.