(Solved): The following question pertains to a study to examine the association between caffeine consumption ...

The following question pertains to a study to examine the association between caffeine consumption and anxiety in college students. The researchers did not consider the timing of their surveys with respect to midterm or final exams. We realize that exams could influence feelings of anxiety and caffeine consumption. In this case, exams could be considered problematic with respect to which of the following? 1) Confounding 2) Healthy worker effect 3) Selection 4) Misclassification