A user reports that a newly installed external CD-RW is not working. Jill, a technician, is called and notes the user has the CD-RW drive, a flash disk, a rarely used external hard drive and a wireless network adapter plugged into an external USB hub. Which of the following is the MOST likely reason for the problem?（）

• A、The USB hub needs more USB ports.
• B、The USB hub is a version 1.1.
• C、The USB hub was not externally powered.
• D、The USB hub is a version 2.0.