Final answer:
When a bar magnet is split into pieces, each piece becomes a separate magnet with its own north and south poles.
Step-by-step explanation:
When a bar magnet is broken into several pieces, each piece becomes a separate magnet with its own north and south poles, making option A the correct answer. This is because magnets are dipolar, meaning they have two poles.
This behavior continues no matter how small the pieces become, as even the most minuscule particles that function as magnets have two opposite poles.
When two magnets or magnetic poles are brought together, opposite poles attract while like poles repel, causing their magnetic field lines to converge or diverge respectively.