Which example of research with prisoners is allowable under regulations?

The option regarding examining age at first arrest as a predictor of adult criminal history is allowable under regulations governing research with prisoners because it investigates the correlation between a specific demographic variable (age at first arrest) and an outcome (adult criminal history) without placing undue risk or stress on the participants. This type of research generally falls within the category of observational studies, which can provide valuable insights into criminal behavior patterns while ensuring that the rights and welfare of the prisoners are prioritized.

Research involving sensitive issues, like violence or prison conditions, can present ethical concerns, particularly regarding participants' emotional well-being and informed consent. In contrast, studying predictive factors such as age does not typically pose the same level of risk or ethical dilemma, making it more acceptable under regulatory standards for conducting research with incarcerated individuals. Thus, option B aligns more closely with the ethical guidelines established for research involving vulnerable populations, including prisoners.