Under conversions in the multi-channel funnels overview report, looking at "all" conversion of the type "google ads" using a 30-day look-back window, what was the percentage of the total conversions for direct traffic? a. 23.87%b. 23.98%c. 34.08%d. 46.97%

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.