A sociologist wants to study a culture that occurs in some women’s prisons: "state families," in which individual prisoners take on certain roles within a group of like-minded prisoners. There is previous evidence that younger prisoners will use older inmates who play the roles of grandparents as a resource before they will turn to staff for help and advice. The lieutenant in charge of a dorm of long-term prisoners offers to gather volunteers to speak to the researcher and also offers to vouch for the integrity of the researcher. The use of this staff is:
a. A valid use of a statistical technique referred to "snowball sampling" wherein the inclusion of the first subject leads to the recruitment of another one subject.b. A useful tactic in obtaining a sample of prisoners who both meet the criteria and who will be honest with the researcher.c. Wrong and is prohibited; subject selection needs to be free from intervention by prison authorities or prisoners.d. Acceptable only when the researcher’s IRB grants a special waiver.