Which of the following refers to a type of monitor that uses a cathode ray tube?

The term that refers to a type of monitor using a cathode ray tube is CRT monitor. CRT stands for Cathode Ray Tube, which is the technology that was commonly used in older television sets and computer monitors before the advent of flat-panel display technologies like LCD, LED, and OLED.

CRT monitors work by using an electron gun to shoot electrons onto a phosphorescent screen, which emits light and creates images. This technology involves bulky hardware and glass tubes, making CRT monitors much larger and heavier compared to their modern counterparts.

In contrast, LED monitors use light-emitting diodes for backlighting, LCD monitors use liquid crystals, and OLED monitors use organic light-emitting diodes. These technologies provide better image quality, thinner form factors, and improved energy efficiency, leading to the decline of CRT monitors in favor of these more modern options.