Which of the following best explains the role of a city under central place theory?
A ) a city servers a function beyond its immediate area by preforming services integral to the world economy
B ) a city provides for a specific ranking of different central places depending on their size
C ) a city exists above a threshold and under a range of economic production as it provides for its surrounding market area
D ) a city marks the minimum provision needed for a central place to be economically reasonable in a given area.