Answer:
prisoners
Explanation:
Prisoners have been popular victims(research subjects) of illegal research in the past and so laws have been put in place to prevent this.
Prisoners are classified as "vulnerable" under federal regulations that regulate research with prisoners. This is because their informed consent and voluntary decision to participate in any research brought before them is somewhat compromised. The health and human services(HHS) in addition to other regulations have added additional requirements for research on prisoners such as the requirement of a prisoner or prisoner representative in the IRB.
