5. Three groups-A, B, and C-were selected randomly to participate in a research study. At the end of the study, an exam was administered and the scores were ana- lyzed via ANOVA, which resulted in a calculated F* value of F(2, 9) = 15.9. If the critical F values are 4.26 for a = .05 and 8.02 for a = .01, respectively, the researcher should report that

a. Group C is superior to Groups A and B at the .05 level of significance.

b. Group B is superior to Group A at the .01 level of significance. C. the differences among the group means could easily have occurred by chance.

d. the differences among the group means are unlikely to have occurred by chance.