According to the federal regulations, research is eligible for exemption, if: a. All the subjects are adults and the risk is minimal. b. The researcher is experienced in the field of inquiry. c. Participation in the research will involve ten minutes or less of the subjects' time. d. The research falls into one of eight categories of research activity described in the regulations.

Option D

Explanation:

Its a regulation, any part that doesn't fall into the same line with the regulation can't be exempted. Regardless of the experience of the researcher or the importance of the research, it has to be in line with the research regulation . that is why we have the regulations ,so that people will be guided and not misguided ,so that the principles in research will be obeyed. So option D explains why a research can be considered exempt, I.e if it is in line with the regulations.