From the list below, which is a valid variable name?

A smart camera may

A) Be on a mobile device that can be used only on a wireless network B) Be on a mobile device that can be used only on a wired network C) Have a mobile operating system, have Internet access, and support wired and wireless networks D) Have no lenses, but be able to rotate 360 degrees, take both front and back pictures, and send signals to a fitness monitor

A customized browser style sheet that trumps all style rules, including location.

a. Media-specific style sheets b. Persistent styles c. User style sheet d. Preferred styles