It is clear that psychology at the individual level, and sociology at the group level provide main contributions. The topics of industrial-organizational psychology, such as motivation, power and leadership, employee training and development, performance appraisal; and in terms of sociology based topics such as inter-group behavior, social categories and systems, small groups and group dynamics are very similar to the topics of OB. As can be understood from the information given, the correct answer is E. All topics in the answer choices are related to industrial-organizational psychology.