Which of the following populations is NOT typically considered vulnerable in research contexts?

In research contexts, populations are often classified as vulnerable when they may have diminished capacity to provide informed consent or are more susceptible to coercion, exploitation, or undue influence. Healthy adults generally do not fall into this category, as they are presumed to have the capacity to understand the risks and benefits of participation in research and are typically able to make informed decisions about their involvement.

In contrast, children, prisoners, and pregnant women are considered vulnerable. Children cannot legally provide consent on their own and rely on parents or guardians, while prisoners may face coercive pressures due to their incarceration status. Pregnant women have specific health considerations and potential risks to both themselves and their fetuses, making them a vulnerable population in research ethics discussions. These distinctions highlight the importance of protecting individuals who may not have the same level of autonomy or understanding in research situations as healthy, consenting adults do.