​The magnetic field lines produced by a bar magnet____________.​

Correct option is A

Correct Answer: A originate from its north pole and end at its south pole

1. Magnetic field lines originate from the north pole and terminate at the south pole of the magnet outside it.
2. Inside the magnet, these lines move from the south pole back to the north pole, forming closed loops.
3. These lines never intersect, as each point in the space around the magnet has only one magnetic direction.

Thus, option A is correct, as magnetic field lines for a bar magnet exhibit this specific behavior.