A study was conducted on the effects of divorce. Researchers gathered data from a random sample of 5,125 adults and measured quite a few variables, in addition to the explanatory variable of divorce and the response variable of shorter life span. According to a newspaper article summarizing the study, those who divorced were more likely to be less physically active, at an unhealthy weight, and smokers. Those who were married were about 15% more likely to be deceased. What conclusion can we draw from this study? Explain. We can infer a cause-and-effect relationship because the sample was selected randomly. We cannot infer a cause-and-effect relationship because we do not have a control group. We can infer a cause-and-effect relationship because multiple variables were included. We cannot infer a cause-and-effect relationship because the treatments imposed were not blocked correctly. We cannot infer a cause-and-effect relationship because treatments were not assigned randomly.