Professor Kramer has decided to measure how happy his students are with his teaching this semester. He is teaching two classes this semester—Psychology and Law and Introduction to Neuroscience. He gives his students a survey.

In the above scenario, what is Dr. Kramer's likely population of interest?
1. All students at the university
2. All students he is currently teaching
3. All psychology majors
4. All students in his Psychology and Law course