Foa, Rothbaum, Riggs, and Murdock (1991) conducted a study evaluating four different types of therapy for rape victims. The Stress Inoculation Therapy group received instructions on coping with stress. The Prolonged Exposure group went over the events in their minds repeatedly. The Supportive Counseling group was taught a general problem-solving technique. Finally, the Waiting List control group received no therapy. Researchers obtained measurements of the dependent variable (the severity rating of a series of symptoms after treatment) for each group, comparing the severity of symptoms between groups. What hypothesis test should you run?