Applying Newton's Third Law

This question relates to Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction.

Analyzing the Forces

Consider the scenario where you are sitting on a chair:

• The force you exert downwards on the chair due to your weight is the action.
• The chair exerts an equal and opposite force upwards on you, supporting your weight. This is the reaction.

Identifying the Reaction Force

The question mentions the force exerted by the chair on you ("the chair exerts an upward force on you"). This upward force *is* the reaction force in the action-reaction pair.

The question asks for "The reaction force in this case". This phrasing refers to identifying the corresponding force in the action-reaction pair. The reaction force to the chair pushing UP on you is the force that YOU exert pushing DOWN on the chair.

Option B correctly identifies this force: "Your weight acting downward on the chair". This is the force exerted by you on the chair, forming the action-reaction pair with the chair's upward force on you.