Answer:
A reaction force
Step-by-step explanation:
The box is not moving downward because the table is applying an equal and opposite amount of force on the box.
This is the premise of Newton's third law of motion which states that "action and reaction are equal and opposite".
The action force impacted by the downward pull on the table is being cancelled out by the upward force of the table.
- The net force in the vertical direction will therefore be 0N
- This way, the box does not move downward.