Answer: Option A
Monitor, provides a visual display of data. A monitor is an electronic display that can display images and text generated by a computer. It is also known as a computer screen or a visual display unit (VDU). In this answer, we will discuss the different types of monitors, how they work, and their applications.
Types of Monitors:

1. Cathode Ray Tube (CRT) Monitors: These monitors were the first type of computer monitors, which use a large vacuum tube to display images. They are bulky and consume more power than modern monitors.
2. Liquid Crystal Display (LCD) Monitors: These monitors use liquid crystal cells to display images. They are thinner, lighter, and consume less power than CRT monitors.
3. Light Emitting Diode (LED) Monitors: These monitors use light emitting diodes (LEDs) to display images. They are similar to LCD monitors but have a better contrast ratio and consume less power.

How Monitors Work:A monitor receives digital signals from the computer and converts them into visible images. The digital signals are converted into analog signals, which are then sent to the monitor's display controller. The display controller converts the analog signals into the appropriate voltage levels that activate the monitor's pixels. The pixels create the images by emitting light of different colors.
Applications of Monitors:

1. Computer Displays: Monitors are commonly used to display images and text generated by a computer.
2. Television: Monitors can be used as a television display when connected to a TV tuner or set-top box.
3. Video Games: Monitors are also used as a display for video games.
4. Security Systems: Monitors are used in security systems to display images from security cameras.

In conclusion, Option A, Monitor, provides a visual display of data. Monitors come in different types, such as CRT, LCD, and LED monitors, and they work by receiving digital signals from a computer and converting them into visible images. Monitors have various applications, such as computer displays, televisions, video games, and security systems.