Select the best answer for the question.
A student conducts an experiment to see how music affects plant growth. The student obtains four identical
plants. Each one is potted in the same type of soil and receives the same amount of sunlight and water each
day. Plant A listens to classical music for three hours each day. Plant B listens to rock music for three hours
each day. Plant C listens to country music for three hours each day. Plant D does not listen to any music at
all.
1. In the experiment described in the scenario, what's the variable?