Need asap !
cassie has a magnet that she holds over an iron nail. the nail moves toward the magnet before the magnet touches it.

which of the following is true about magnetism?
a.
magnetism is a force that must directly touch an object in order to move it.
b.
magnetism is a force that acts at a distance and cannot be seen.
c.
magnetism is not a force, and therefore it cannot move an object.
d.
magnetism is a force that can be seen in the air as it moves an object.