For the sake of convenience, what parameter type can be used when the variable to be passed does not have an assigned value at the time the method is called?

Windows 7's Help and Support feature is available:

A) from the desktop. B) from the Start menu. C) from the taskbar. D) in the Notification area.

Which of the following is recommended to reduce energy consumption?

A. Turning off peripherals when not in use B. Turning off monitors when not in use C. Turing off computer when not in use D. All the above