Final answer:
Airports depicted with a circle symbol are simply represented this way on maps, not indicating circular runways. Those with large runway symbols represent their runway layout. These symbols help to distinguish different types of airports within the civil airline infrastructure.
Step-by-step explanation:
The difference between an airport symbolized with a circle and one with a large runway(s) representation on a map or chart is the way they are depicted to indicate various types of airports. Option D) Circle airports are depicted with a circle symbol, while large runway airports are depicted with a rectangular symbol is the correct answer. It's important to note that a circle does not mean the airport has circular runways, nor does it indicate anything about the airport's control tower or whether it is private or public. These symbols are a part of the development of a civil airline infrastructure, with airport terminals facilitating the boarding of airplanes and handling of luggage, key components for the efficiency of commercial passenger air traffic.