the answer is: A cognitive psychologist enrolls undergraduate students for a computer-based study about the effect of mood on problem-solving behaviors.
Here the requirement for research with human subjects according to the Fed :
"Obtains information or biospecimens through intervention or interaction with the individual, and uses, studies, or analyzes the information or biospecimens; or Obtains, uses, studies, analyzes, or generates identifiable private information or identifiable biospecimens."
The experiment on this ption fulfill the criteria because:
- The experiment should use studies or analytics to obtain some sort of private information from the subjects. (such as their mood)
- The experiment should make some sort of intervention that can be used to measure its hypothesis. (in the case above, the researchers could put the subject under a certain level of stress before telling them to solve a set of problems)
- The researchers need to interact with the subject in a certain way. (since the researchers meet the undergraduate directly, it's considered as an interraction)