The answer is the fourth option. Put the compass point on A and the pencil point on the segment, closer to point B than to point A, and draw a circle centered at point A. Without changing the compass opening, draw a circle centered at point B. The diagonals of a square bisect each other in mutually perpendicular. Let AB be the diagonal, when we draw a perpendicular to the diagonal AB the other two points of the square are in this perpendicular.And are in opposite sides.So we draw the two circles with same radius less than AB and greater than half of AB.
