Professor Williams Wants to Know If "Real" College Students Exhibit

Professor Williams wants to know if "real" college students exhibit the same kinds of behaviors in class that subjects who were paid to act like college students do.She decides to have someone come in once a week to her classes to record the types of nonverbal behaviors that students engage in while listening to her lectures.This would be an example of which kind of study?

A) Real-world observation
B) Naturalistic observation
C) Classroom observation
D) Social observation