Jeremy wanted to make some extra money in the summer so he opened up lemonade stand in front of his house. Before he could sell cups of lemonade he had to purchase $12 in cups, sugar, and other materials to build the stand. The total amount Jeremy made on his lemonade stand is modeled by the function A(x) = 2.5n - 12 where A is the total amount he made on n cups of lemonade sold. Which best describes the rate of change in this function? A. The average number of customers Jeremy had.
B. The amount of money Jeremy made on each cup sold.
C. The maximum amount of money Jeremy made.
D. The total number of cups of lemonade Jeremy sold.