Amultiple-regression analysis is run to examine third variables as a follow-up to the study indicating that boys with unusual names are more likely to commit crimes. unusual names, ethnic backgrounds, and geographical regions are all included as predictor variables. even after controlling for all of these variables, unusual names still predict criminal activity. why doesn't this study establish causation? a. temporal precedence isn't establishedb. the beta values are not shown, so there isn't enough information to conclude causationc. there may be some other third variabled. no cross-lag correlation was done