Answer:
Cohort study
Step-by-step explanation:
A cohort study is a type of longitudinal study (a study where repeated observations are taken in a period of time) where the sample consists of people who share a common characteristic.
In this example, the researcher identifies two groups of COLLEGE students in a MATH class. The group who drinks more than 5 alcoholic drinks at one time and the group who doesn't. We can see that both these groups share the characteristic of being math college students (therefore we can conclude that they share some interest and they were most likely born around the same years). Then, after one semester the researcher measures their performance in their final exam (thus this is a longitudinal study, were the observations were made over the course of one semester).
Since it's a longitudinal study and the sample shares some common characteristics (math college students) we can conclude that this is an example of cohort study.