The scatter plot shows the number of albums sold from 2006 to 2011. What is the association between the two quantities? A. Positive linear association.
B. Negative linear association.
C. Positive nonlinear association.
D. No association.

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.