D
The larger the number the warmer it is
The outlier is a because it is the most different value compared to the rest.
If each player will receive 7/8 of a cup, and there are a total of 20 cups of lemonade, then the number of servings that can be made is equal to:
20 cups divided by (7/8 cup per player)
20 / (7/8) = 20 * (8/7) = 160/7 = 22 and 6/7 (round down since we're looking for complete servings)
This means that 22 complete servings can be made.