Which of the following is an explanatory thesis?
A.Streaming music services are unfair to musicians: they reduce royalties and impact how artists make a living.
B. Music streaming services can be a powerful promotional tool for artists if they use the sites wisely.
C. Some contend that streaming music online is unfair to musicians, while proponents of the technology focus on the benefits of these services to consumers.
D. Online music streaming is a beneficial element in the music industry; it decreases music piracy and increases the exposure of new artists and styles.