A Psychologist Wants to Know If Adults with Normal Vision

A psychologist wants to know if adults with normal vision can be fooled by a certain optical illusion. She recruits 50 students from her PSY 120 class and finds that 42 of them are fooled by the illusion. The population in this study is

A) the 42 students who were fooled.
B) the 50 students who served as subjects.
C) all students in the PSY 120 class.
D) all adults with normal vision.