A golf course has 18 holes. A guidebook provided to golfers includes useful information about each hole. The individuals in this data set are shown. Hole Number Yards Bunkers Difficulty Level 1 312 2 moderate 2 530 5 moderate 3 147 1 easy 4 350 0 moderate 5 410 2 hard 6 185 1 moderate Which of the variables in the data set is a categorical variable?