Apple's iPod sold more than $50$ million units annually between $2001$ and $2010$ when the iPhone integrated a music player. Since then sales have been declining dramatically and in $2014$ Apple announced that it was discontinuing the iPod classic, and in $2017$ it did the same with the nano and the shuffle. Today Apple still sells the iPod touch although declining sales and discontinued products suggest that this SBU is has become a

Multiple Choice

star.

question mark.

cash cow.

ghost.

dog.