Which type of research involving prisoners is acceptable under the regulations?

The choice that involves examining age at first arrest as a predictor of adult criminal history is acceptable under the regulations concerning research with prisoners. This type of research can be considered ethical and justified because it relates directly to the prison population and aims to gather information that may benefit understanding within the context of criminal behavior and correctional systems.

Research involving prisoners is heavily regulated to ensure their rights, welfare, and informed consent are protected. When studies offer insights that could improve interventions or policies affecting incarcerated individuals, such research can also be seen as having the potential for social benefit. In this case, focusing on factors like age at first arrest directly correlates with their experiences and circumstances, thereby aligning with the ethical guidelines for conducting research in sensitive populations.

The other options either do not pertain directly to the prison population or lack the sufficient relevance to address issues unique to the correctional system, which is a key criterion for approving research involving prisoners.