Wheels from a toy cart are rolled from a concrete sidewalk onto the following surfaces: A, a paved driveway; B, a grass lawn; and C, close-cropped grass on a golf-course putting green. Due to slowing, each set of wheels bends at the boundary and is deflected from its initial straight-line course. Rank the surfaces according to the amount each set of wheels bends at the boundary, from greatest amount of bending to least. Explain your answer.