You are curious if doing a study group helps improve performance in your statistics course. You randomly pick half of the class to do study group and the rest of the class will not do any study group. After the semester goes by, you compare the performance of students who did the study group vs those who did not. Is this anecdotal data, available data, an observational study, or an experiment? A. anecdotal data
B. available data
C. observational study
D. experiment