The correct answer to this open question is the following.
The question does not provide options, but we can say the following.
The federal regulations state that the IRB must conduct continuing review of research approved by a convened IRB (more than minimal risk research) at intervals appropriate to the degree of risk, but not less than once per year. The continuing review must be periodical.
IRB stands for Institutional Review Board. This office was created to protect the rights research about human issues. To do this, IRB has to examine the questions that are to be asked to humans in a survey because it needs to guard people's privacy. That is why IRB can approve or not research on humans, and in any case, can order modifications to the surveys.