Concept:Computers are classified based on technical features such as purpose, size/capacity, and data handling, not colour.
Explanation:Computers can be classified by purpose, for example general-purpose or special-purpose.
They can also be classified by size and capacity, such as microcomputers, minicomputers, mainframes, and supercomputers.
They can be classified by data transmission or type of data they process, such as analogue, digital, or hybrid computers.
Colour is not a recognised basis for classifying computers.
Answer:A. colour.