Candice learns that all magnets have two magnetic poles. which of the following observations would best support this statement?

a.) the north pole of a compass needle is attracted to the south pole of a bar magnet.

b.) when a bar magnet is cut in half, each half has a north pole and a south pole.

c.) the strength of a horseshoe magnet's magnetic field decreases as the magnet is pulled away from another object.

d.) when an electric current flows through a wire, a magnetic field forms around the wire.