A researcher hypothesizes that students who listen to classical music while studying will perform better on exams than students who study listening to rock. In this study, the independent variable is ______; the dependent variable is ______.

A) type of music; students
B) exam score; type of music
C) students; exam score
D) type of music; exam score

The independent variable is the variable that is being manipulated by the researcher, which in this case is the type of music (classical or rock) being listened to while studying. The dependent variable is the variable that is being measured, which is the exam score. Therefore, the best choice is D as it correctly identifies the independent variable as type of music and the dependent variable as exam score.