A group of educational psychologists want to know if their intervention will change student's performance on the SAT. These researchers recruited 10 students from a university and asked them to come to their lab. Among 10 students, 5 of them were randomly assigned to the experiment group and 5 were assigned to the control group. The intervention group were asked to prep-class and then take the SAT. On the other hand, the other five students took the SAT exam without taking any class. According to the information given, which t-test would you suggest the researchers use?