I would go with C. The candidate could have been in the program before 1990 and still take Macroeconomics. He could also have taken Macroeconomics between 1990 to 1995. Hence C is the possible answer.
_________________

The path is long, but self-surrender makes it short;
the way is difficult, but perfect trust makes it easy.

It should be E ..name of the Business school is needed

E

Easy E.

Going with E

but i think c is a possibility too

In a Venn diagram, C would be inside E. What C is missing, I think, is the possibility of the student starting before 1990, in which case the Micro seminar could or could not be a Must.
My vote is E. OA?

E 2

In the Business program at a university, all candidates for the MBA in International Business who entered the program after 1990 took a seminar on Microeconomics, and all candidates for the MBA in International Business who entered the program after 1994 took a seminar on Applied Economics.

If a student in the Business program described above took a seminar on Microeconomics but did not take a seminar on Applied Economics, which of the following must be true? ( Microeconomics + Not Applied Economics) --> ???

Candidate who entered the program in 1990 + (1991 through 1994) --> Microeconomics
Candidate who entered the program in 1994 + (1995 to the present) --> Applied Economics

If Mircoeconomics we cannot infer that it was 1991 through 1994 because this is a sufficient condition.
Not Applied Economics --> not after 1994 (1994 and before)

A. The student entered the Business program prior to 1995.
This statement could be true. However, we must eliminate this choice because we cannot ensure that a candidate for the MBA in 1975 took Microeconomics.
B. The student entered the Business program after 1990 and prior to 1995.
My choice. This follows directly from the statements above.
C. If the student was a candidate for the MBA in International Business, then the student entered the program prior to 1995.
This is wrong for two reasons. This means that all candidates entered the program. Too strong! Additionally, we must eliminate this choice because we cannot ensure that a candidate for the MBA in 1975 took Microeconomics.
D.If the student was a candidate for the MBA in International Business, then the student entered the program prior to 1991.
Eliminate. This means all students who applied attended the school. This is too strong.
E. If the student was a candidate for the MBA in International Business, then the student entered the program after 1990 and prior to 1995.
Eliminate. This means all students who applied attended the school. This is too strong.

Who is a candidate for MBA in IB? A student who has been admitted and fulfilled the course requirements, not all those who applied.

Stem is talking about candidates for MBA in IB not about MBA in Finance or marketing.

B has broader scope. In other words we only know about candidates for MBA in IB. It is very well possible that a marketing MBA candidate who might have entered the program after 1990 or before 1995 might fit this or might not fit this. We cannot apply it to the entire business program.

Hence E.