The correct option is (a) smaller areas
The explanation is: For locating the position of the centre of gravity of an area of unsymmetrical shape, it is first divided into a number of Smaller areas of symmetrical shapes such as triangle, squares, rectangles, trapezoids etc. so that the centre of gravity of each such area is easily determined. Each small area is then treated as a force proportional to the area and acting at the centre of gravity of the area.