Which of the following monitors has only two colours

A monitor that has only two colors is called a monochrome monitor. This type of monitor is capable of displaying only two colors - typically black and white.
Monochrome monitors were commonly used in the early days of computing, when color displays were not widely available or affordable. These monitors were simpler in design and used only one color for displaying images and text.
The advantage of a monochrome monitor is its simplicity and cost-effectiveness. It requires less processing power and memory to display images and text in just two colors. This made it suitable for many applications where color was not a crucial requirement, such as word processing, programming, and data entry.
However, the limitation of a monochrome monitor is the lack of color representation. It cannot display images or graphics with the same level of detail and realism as color monitors. As technology advanced, color monitors with higher resolutions and better color accuracy became more popular and affordable.
In summary, a monochrome monitor is a type of monitor that can only display two colors - typically black and white. It was commonly used in the early days of computing for applications that did not require color representation.