One Device Used as an Input Device in a Computer

Multiple Choice

One device used as an input device in a computer system is a pointing stick, which is best described as:

A) A small gearshift lever set in a box
B) A stationary device containing a roller ball whose top is exposed outside its case
C) A pen-shaped device with a ballpoint at the end
D) A small, button-like device, sometimes likened to the eraser head of a pencil