Which of the following is ideally suited to get a digital copy of a content…

Concept: Computer peripherals are classified by the direction in which data travels. An input device carries data from the outside world into the computer; an output device carries data from the computer out to the physical world. Digitisation is the input operation that turns an artefact which already exists physically into a machine-readable file by optically sampling its surface point by point.

Application: The stem asks for content that already exists on a paper sheet to end up as a digital copy, so two conditions must hold at once - the data must travel from the paper into the computer (an input device), and the capture must be optical across a whole printed surface rather than typed, pointed or drawn. A scanner meets both: a lamp illuminates the sheet, a CCD or CIS sensor samples the reflected light line by line, and those samples are assembled into a raster image file, which OCR software can further convert into editable text.

Cross-check - what each listed device actually does:

Result: only the scanner both moves data from paper into the computer and captures it optically, so the scanner is the device ideally suited to producing a digital copy of a printed sheet.