2. As shown in the diagram below, when right triangle DAB is reflected over the line m, its image is triangle
САВ. .
m
D
Which statement justifies why CB = DB?
O A. Distance is preserved under reflection.
OB. Orientation is preserved under reflection.
OC. Points on the line of reflection remain invariant.
OD. Right angles remain congruent under
reflection

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.