which statement correctly describes magnetic field lines?
a. they never cross,
b. they always point toward a north pole.
c. they never connect.
d. they always point away from a south pole.

They never cross

Explanation:

A. They never cross

Explanation:

The magnetic field lines cannot be crossed, since this would mean that there would be more than one value for the magnetic field at the same point, that is, at the point where the lines intersect. Therefore, the resulting magnetic field vector at a point in space, where the field takes place, is unique.

see earlier answer

current flows in a wire