Theresa is conducting a study to assess the effects of calming music on test performance. She gives a brief intelligence test before exposing participants to calming music and then retests the participants with the same intelligence test. The participants' increases in test scores may be due to .

both testing effects and the effects of the calming music

Explanation: A brief intelligence test helps reinforce learning and makes it more likely that the participants can retrieve related information later as it is more likely to retain information if it is learned separated over time. Calming music may improve test-taking skills, improve performance, reduce stress and test anxiety of the participants and well as improving concentration. Therefore, the participants' increases in test scores may be due to both testing effects and the effects of the calming music.