Concept:A freely suspended magnetic bar aligns itself with the Earth's magnetic field in the North-South direction.
Explanation:When a steel bar is suspended horizontally at its midpoint, it is free to rotate.
If the bar is magnetized, it behaves like a compass needle.
Therefore, the bar will always come to rest in the magnetic N-S direction.
Attraction by a magnet is not conclusive because an unmagnetized steel bar can also be attracted through induction.
For a bar suspended in this way, consistently settling in the N-S direction is the conclusive test for magnetism.
Answer:A. always settles in the magnetic N-S direction.