The School Board Abolished an Old Regulation That No Students

The school board abolished an old regulation that no students from Country X would be admitted. The regulation had been put in place because the board had believed (at the time) that people from Country X were less intelligent and unable to achieve appropriate academic standards. The reasoning for this old regulation is an example of which of the following?

A) prejudice
B) normative theory
C) frustration-aggression
D) primordialism