Answer:
D. two objects, when touching, will exert forces on each other that are equal in strength but opposite in direction
Explanation:
The three Newton's Laws have to do with force interaction in bodies. Option A follows other laws that are not from Newton. Option B has more to do with energy conservation, not forces. Option C is actually one Newton's Law, but it's the second one. It describes how an object with certain mass changes its force as long as the body is in certain type of acceleration.
Finally, option D is Newton's Third Law and describes how two bodies with mass interact each other when they touch. Ine very body interaction, there al always 2 forces that meet, and depending on which angles they encounter, the resultant force can vary.
For example, when a person sits down, there's a force coming from him towards the chair; but at the same time, the chair pushes the body back with exactly the same force. There's no movement at all from the 2 bodies because the whole system is in equilibrium or the resultant force is equall to 0.
