400
Weaken this conclusion...
Five of the seven GMAT students from the fall semester are in the MBA program. Therefore, you should take the GMAT prep class if you want to enter the MBA program.
What is a) the students were good autonomous learners b) they had other classes that contributed to their passing c) they had already received a high enough score to enter the MBA program, but wanted to raise it more d) their score before taking the class was close to the needed score to be admitted into the program?