How did rule of law influence our political systems?

Whether or not a given study has the possibility of causing harm to participants:

Which of the following are ways that a citizen can address issues in the nation? learn how government works first. give money to special interest groups. volunteer to special interest groups. study the record of representatives and vote in elections. employ executive restraint in the office of the u.s. president.

Dr. laguardia is a cognitive neuroscientist who is interested in the effect of brain concussions on the ability to recognize faces. he conducts a quasi-experimental study in which he examines football players before and after the regular season using the benton facial recognition test (a published, widely used measure of one's ability to recognize faces) to compare those who received concussions to those who did not. he finds that players who had concussions during the regular season performed worse on the benton facial recognition test than did players who did not experience which of the following is true regarding external validity in dr.laguardia's study? a. because dr. laguardia selected participants who actually experienced concussions, the study b. because dr. laguardia's study is a quasi-experiment, it is impossible to obtain c. because dr. laguardia's dependent variable was assessed in the laboratory, the study d. because dr. laguardia selected a widely used measure, his study generalizes to has strong external validity. external validity has limited external validity. other applications of this measure.