In each problem, out of the four figures marked (a) (b) (c) and (d), three are similar in a certain manner. However, one figure is not like the other three. Choose the figure which is different from the rest.
1, 2, 5 are figures that have patterns formed from four lines curved in a concave direction. 3, 7, 8 are figures that have patterns formed from four lines curved in a convex direction. 4, 6, 9 are figures that have patterns formed from these straight lines.