In magnetism, unlike poles attract. This means that when you have two magnets, the north pole of one magnet will attract the south pole of another magnet. This is due to the magnetic field lines that travel from the north pole of one magnet to the south pole of another, creating an attractive force between them.
On the other hand, like poles repel each other in magnetism. So, if you try to bring two north poles or two south poles of magnets close together, you will feel a force pushing them apart. This repulsion occurs because the magnetic field lines from each pole are in the same direction, leading to a repulsive force between them.
Therefore, the correct answer to the question is:
A. unlike poles attract
