A researcher is studying the black market economy in a socialist country. She will make preliminary contact in the streets with people who are selling goods illegally as if she were a potential buyer and then invite them to be in her study. She is of the same ethnicity as her potential subjects and fluent in their language. After arranging to meet potential participants in a secure location the researcher should:a) Provide detailed information about the study and secure voluntary oral agreements to participate in the interview without documentation of consent. b) Secure voluntary oral agreement to take part in the study, and require the participants to sign two copies of an informed consent form, so that they have one to keep for their records. c) Use an unobtrusive recorder, ask subjects to state their names at the beginning of their taped interviews, and then use pseudonyms when reporting. d) Secure written documentation of consent, and mail signed consent forms to the U. S. once a week for safekeeping.