Which one of the following statements with regard to Newton’s third law of motion is correct ?

The correct answer is Option 3. Newton’s Third Law states that for every action, there is an equal and opposite reaction. This inherently implies a cause-effect relationship where the "action" serves as the cause and the "reaction" is the immediate effect.

• Why Option 3 is correct: The law defines the interaction between two bodies. When Body A exerts a force (cause), Body B simultaneously exerts an equal force back (effect). Without the initial action, the reaction cannot exist, establishing a logical causal link.
• Regarding other options: While it is true that forces occur in pairs (Option 1) and a stone pulls the Earth (Option 2), these are descriptions of the law's application rather than a conceptual statement about its logical structure. Option 4 is incorrect because denying the cause-effect link contradicts the fundamental principle of interaction where one force necessitates the presence of the other.

In the context of classical mechanics, the "action" is the causative agent that triggers the "reaction," making Option 3 the most conceptually accurate statement regarding the law's implication.