Which of the following is not an input device?

"Line partnership" is not an input device. Input devices are used to input data or commands into a computer system for processing. A "card reader" is a device that reads data from a magnetic stripe or barcode on a card, while a "paper top reader" is a device that reads data from a sheet of paper. An "alpha-numeric keyboard" is a device that allows a user to input text and numbers using a keyboard. However, "line partnership" is not an input device; it is not a device at all, but rather a business term referring to a type of partnership.