Consider the following 3 scenarios. 1. Researchers wish to investigate a possible effect of caffeine on athletic performance. II. Researchers wish to investigate a possible relationship between embezzlement and alcohol use. III. Researchers wish to investigate a possible relationship between a daily intake of pomegranate juice and sleep quality. Which of these scenarios would best be carried out as an experiment rather than an observational study or survey? Just I. I and II. I and III. II and III. All of them.