Large cities are fewer in number and farther apart than medium-sized cities; medium-sized cites are fewer in number and farther apart than small cities. what theory accounts for the regularities of size and spacing of cities as market centers?

Rank size rule of cities given George zipf

Explanation:

It is a distribution of cities based on ranking their sizes as compared to others. This law states that there exists a remarkable regularity in the distribution size of cities and businesses, this ranking is also influenced by the population living in the cities.  Thus farther apart cities tend to have a smaller size and varying further as the spacing grows. The main cause that leads to the growth of cities is there power to attract customers like centers of economic growth. like a city with rank three would have one-third the population of a country's largest city, ans a rank four city would have one-fourth the population of the largest city.

F=31 because you subtract 39-8

Iwould choose c or d