The magnetic field is strong near the of a magnet.

The magnetic fields of magnets are most powerful at the poles of a magnet. Without any difference in the magnitude, both the poles have equal amount of Magnetic field intensity at their poles.

If you see the field lines we can see the field lines start from the North Pole run parallel and end at the South Pole.  The field lines are concentrated more at the poles hence the magnetic field intensity or the magnetic field itself is more at the poles than any other part.

the answer is a. hope this .