You Are Conducting an Experiment to Determine If Listening to Music

Multiple Choice

You are conducting an experiment to determine if listening to music improves learning.If the average test score of the experimental group is higher than the average of the control group,
Then we can conclude that

A) extraneous variables were not controlled.
B) the two groups were not randomly assigned.
C) listening to music improved learning.
D) listening to music does not improve learning.