What is the range of the function on the graph? all the real numbers all the real numbers greater than or equal to 0 all the real numbers greater than or equal to 2 all the real numbers greater than or equal to –3

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.