A square is split into four parts. The shaded part and the black dot both move at every step, but not in the same direction. Find the next figure.

The shaded part moves one place clockwise (top-left, top-right, bottom-right, bottom-left) and the dot moves one place anticlockwise (bottom-right, top-right, top-left, bottom-left). Next the shading returns to the top-left and the dot goes to the bottom-right: (b). (d) leaves the dot where it was and (c) moves the shading twice.