What ethical requirement must researchers fulfill regarding vulnerable populations?

Vulnerable populations, such as children, prisoners, or individuals with cognitive impairments, often require additional ethical considerations when conducting research. The ethical requirement to ensure enhanced protections stems from their increased susceptibility to coercion or harm and their potential inability to fully understand the research process or give informed consent.

Enhanced protections may include obtaining consent from a legal guardian for minors, ensuring that participation is truly voluntary without undue influence, and implementing measures to safeguard their well-being throughout the study. This aligns with ethical guidelines such as those outlined in the Belmont Report, which emphasizes respect for persons and the need for special considerations for marginalized or at-risk groups.

The other options, while important in their own right, do not directly pertain to the ethical obligation of researchers in relation to vulnerable populations. Increasing sample size and gathering more funding are logistical aspects of research design, and limiting publication of results does not protect vulnerable individuals but rather obstructs transparency and dissemination of knowledge.