A researcher examines the physical attractiveness of a driver involved in an automobile accident (unattractive, average, or attractive) and the severity of damage caused ($500, $1500, or $2500) on judgments of responsibility assigned to the driver. Which of the following represents the design?
a. 2 x 2
b. 2 x 3
c. 3 x 3
d. 1 x 3