Determine whether the following study is an observational study, an experiment, or a meta-analysis, and explain your choice. A survey given to students in a university cafeteria asks students about their opinions about text messaging. Choose the correct answer below. A. The study is an observational study because there was no attempt to influence the results. B. The study is a meta-analysis because an analysis of the data was used to determine effectiveness. C. The study is a meta-analysis because the study was done on a group. D. The study is an observational study because the data were collected all at once. E. The study is an experiment because there is a treatment group and a control group. F. The study is an experiment because a hypothesis is tested.