Answer:
Research about aptitude testing
Step-by-step explanation:
IRB is Insitiutional Review Board who protects the rights of human subjects in research work of the people.
If the research is subject to Subpart D of the 45 CFR Part 46, research involving education test of children or the aptitude test of children or diagnostic and achievement test of the children is exempted.
Research done on the testing the aptitude of children is exempted under Category 2 of exemption.
Thus the answer is
"Research about aptitude testing".