Final answer:
Screensavers protect a computer monitor's screen from burning in by changing the display at short intervals to prevent image retention or burn-in.
Step-by-step explanation:
The correct answer is a) Screensaver. Screensavers are designed to prevent screen burn-in by changing the display at short intervals. When a computer monitor displays the same image for an extended period, it can result in image retention or burn-in, where ghostly images remain on the screen even after the image has changed.
Screensavers were initially developed to prevent phosphor burn-in on CRT monitors, but they are still relevant today for LCD and OLED screens. By displaying moving images or patterns, screensavers help distribute the wear across all pixels and reduce the chances of burn-in.
For example, if a static image, such as a company logo, is continuously shown on a monitor for a long time, the pixels that create the image can degrade unevenly. But with a screensaver that changes the display periodically, all the pixels on the screen are used equally, preventing burn-in.