Fei yen's dog eats 8 ounces of dog food each day. fei yen's bought a 28 pound bag of dog food. how many 8 ounce servings are in a 28 pound bag of dog food?
a)14
b)56
c)224
d)448

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.