Karen debriefs her participants. This means:
1) Before the study occurs, she tells them what the study is about and asks if they'd like to participate
2) She includes an actor who pretends to be another participant in her study
3) At the end of the study, she explains to participants any deception that was used during the study
4) She explains to the IRB how she will protect participants' well-being and avoid harming them
5) All of the above