A device that sends and receives printed pages or images over telephone lines by digitizing the material with an internal optical scanner and transmitting t...

The device described here has three specific features working together: it scans a physical document using an internal optical scanner, converts the scanned image into electronic signals, and sends those signals over a telephone line so that a matching device at the receiving end can reconstruct and print the page. A device performing exactly this sequence, scanning, digitising, transmitting over phone lines, and printing a copy at the other end, is a fax machine.

A cash-dispensing terminal used for banking transactions has nothing to do with scanning or transmitting documents over telephone lines, so it does not match any part of the description. A plain scanner does digitise a document into an electronic image, but it does not transmit that image over telephone lines on its own; scanning alone stops at creating a digital copy on a connected computer. A mobile communication standard is a technology used for voice and data transmission over cellular networks, not a physical device that scans and sends printed pages, so it does not fit the description of a device at all.

The clue that should stand out in this kind of question is the specific pairing of "optical scanning" with "transmission over telephone lines," since that exact combination is unique to a fax machine and does not describe any of the other devices.