Evolution of Scenario C along the WD cooling sequence. Left: B_r as a function of radius for three different cooling ages: t_cool = 0Gyr (dark blue), t_cool = 0.2Gyr (purple), and t_cool = 8Gyr (yellow), with the colored circles emphasizing the current field strength at the surface. Right: B_r at the surface of the WD as a function of cooling age. The three colored circles correspond to the surface field strength of the three radial profiles in the left panel.