The magnetic force is strongest at position C. (Option D).
Where is the magnetic force the strongest?
The magnetic force is strongest at the poles of a magnet. A bar magnet has two poles, a North Pole and a South Pole.
The magnetic field lines originate from the North Pole and terminate at the South Pole. The force is concentrated and strongest around these poles.
As you move away from the poles, the strength of the magnetic field decreases. The strength of the magnetic force is at its maximum at the poles and diminishes as you move towards the center of the magnet.
Thus, based on the diagram, the magnetic force is strongest at position C.