Roshanda was curious if students in her class would complete a maze faster if fast-paced music was playing in the background. She randomly assigned each student in her class to one of three groups: fast-paced music, slow-paced music, or no music. She timed each student as they individually completed a maze with their corresponding music (or no music) in the background. Students who worked with the fast-paced music, on average, completed the maze significantly faster than students in the other groups.
Can we conclude that the fast-paced music caused her classmates to finish the maze faster? Why?

(A) Yes, because the study included each student in her class

(B) Yes, because the adults were randomly selected

(C) Yes, because the students were randomly assigned to treatment and control groups

(D) Not necessarily, because the sample size was too small

(E) Not necessarily, because this wasn't an experiment