The Recording Industry Is Similar to the Book-Publishing Industry in Which

The recording industry is similar to the book-publishing industry in which key way?

A) Both are continuing to lose money.
B) Both are gaining more artists or authors because of the Internet.
C) The vast majority of releases in both industries sell less than 5,000 copies per year.
D) Most of the sales volume in both industries comes from a myriad of authors or artists, numbering in the tens of thousands.