Choose the incorrect statement from the following regarding magnetic lines of a field
(a) The direction of the magnetic field at a point is taken to be the direction in which the north pole of a magnetic compass needle points
(b) Magnetic field lines are closed curves
(c) If magnetic field lines are parallel and equidistant, they represent zero-field strength
(d) Relative strength of magnetic field is shown by the degree of closeness of the field lines
