Julia and David conducted a study on 74 5^th grade students who were randomly assigned to groups.One group listened to pop music, a second group heard easy-listening music, and the third group heard no music.While the music (or no music) was going on, students read a short story.Later the students took a test that measured their comprehension of the short story.Type each answer in red beside each question.

(A)The independent variable was:

(B)The number of levels of the independent variable was:

(C)The dependent variable was In Julia and David's experiment the scores of the 74 students on the comprehension test are the dependent variable