Polygraph results are not admissible in U.S. courts

If students who complete a study skills course raised their grade point averages, can we conclude that the course caused their improvement?

a. Yes, because the scientific data was collected. b. Yes, because a negative correlation exists between these students' grade point averages before and after taking the course. c. Yes, because the course resulted in a self-fulfilling prophecy. d. No, because there was no control group.

According to self-determination theory, there are three basic and universal psychological needs: autonomy, competence, and _______________

Fill in the blank(s) with the appropriate word(s).