Which of the following statements about iron filings placed upon glass resting on top of a bar magnet is false?

a. the direction of the flux in the portion of a magnetic field outlined by the filings will be from the north pole of the magnet to the south pole.
b. the filings will sit on the glass on curved paths between the north and south poles.
c. the density of the filings will match the intensity of the magnetic field.
d. the filings will be clustered more densely where the field is weakest.