1.Dr. Raiden is interested in testing the effects that self-defense classes have on the academic performance of students.He randomly selects 20 students from each class (Freshman, Sophomore, Junior, Senior) from a complete student list for MK University and randomly assigns half of the students from each class to a control group and the other half to the experiment group.The 40 students in the experiment group take a self-defense class twice each week for the entire semester.The 40 students in the control group do not take the self-defense classes during the semester.At the end of the semester, the GPAs of the students in the control and experiment groups are recorded and compared.

a.(1 pt) What is the treatment imposed in this experiment?

(1 pt) What is a possible lurking or confounding variable for this experiment?