The correct answer is C. Touch screen used for computer input.
A pointing device is an input device that allows a user to interact with a computer by moving a cursor or pointer on a screen. Common pointing devices include the mouse, trackball, touchpad, and touchscreen.
A hard disk is a storage device that stores data on magnetically coated platters. It is a non-volatile storage device, which means that it retains its data even when the power is turned off.
A CD-ROM drive is a device that reads and writes data to compact discs. It is a storage device, not a pointing device.
RAM is a type of memory that is used to store data that is currently being used by the computer. It is a volatile storage device, which means that it loses its data when the power is turned off.
A touchscreen is a display that allows a user to interact with a computer by touching the screen. It is a pointing device.