The correct answer is: C. lower edge towards the upper edge.
Superelevation is a banking of a road or railway curve to counteract the centrifugal force experienced by vehicles traveling along the curve. The rolling of the pavement on a superelevated curve should proceed from the lower edge towards the upper edge to ensure that the pavement is properly compacted and that there are no voids or bumps in the surface.
Option A is incorrect because rolling from the sides towards the center would not compact the pavement evenly. Option B is incorrect because rolling from the center towards the sides would not compact the pavement evenly. Option D is incorrect because rolling from the upper edge towards the lower edge would not compact the pavement evenly.