When might an IRB chair inform a principal investigator that research can begin immediately?

The correct choice indicates that an IRB chair can inform a principal investigator that research can begin immediately when the project is exempt from further review. This is aligned with the ethical guidelines outlined in the Belmont Report, which emphasizes the importance of protecting human subjects in research. Certain types of research are classified as exempt under federal regulations, meaning they do not pose greater than minimal risk to participants or meet specific criteria allowing for exemption. Therefore, when a project is recognized as exempt, the IRB chair can grant permission for the research to commence without requiring additional review or oversight.

In contrast, situations where the project requires no funding, all subjects have agreed to participate, or a researcher has prior experience may not directly affect the necessity of IRB review or the timing of when research can start. These factors do not inherently pertain to the IRB’s decision-making criteria regarding ethical approval and oversight based on the nature of the study. Thus, they do not provide a basis for immediate initiation of research, as the IRB's mandate focuses on the protection of human subjects and adherence to established protocols.