Final answer:
Cloud-based music services are popular because they offer consumer choice, better-quality data transmission, and new technology for artists to reach wider audiences. Cheaper phone calls and a potential return to physical media are not reasons for their rise in the mobile music business.
Step-by-step explanation:
The question pertains to the reasons why cloud-based music services are gaining popularity and which option is not a reason for their increasing impact on the mobile music business. The listed reasons include more consumer choice, cheaper and better-quality data transmission, and emerging technologies such as free Internet-based calling and video calling. Another reason is the ability for artists to find a far-flung audience through web-based commerce. These reasons all contribute to the popularity of cloud-based music services by offering convenience, affordability, better quality, and wider distribution channels. However, statements highlighting the cheaper costs of phone calls or the potential transition back into physical media do not directly relate to the rise of cloud-based music services. These might refer to telecommunications and media consumption trends more generally, but not specifically to cloud-based music platforms.