The correct answer is: C. assumes.
The word “assumes” means “to take something for granted” or “to suppose that something is true”. In this case, the test assumes that any graduate is expected to complete it successfully. This means that the test does not require any previous knowledge of the subject.
The other options are not correct because they do not convey the same meaning. The word “concerns” means “to be relevant to” or “to be about”. In this case, the test does not concern previous knowledge of the subject. The word “presupposes” means “to take something as a necessary condition for something else”. In this case, the test does not presuppose previous knowledge of the subject. The word “necessitates” means “to make something essential or unavoidable”. In this case, the test does not necessitate previous knowledge of the subject.