Transportation in the city of Los Angeles is dominated by the automobile. According to Borchert’s model on the development of cities this is because the city emerged in the early to mid twentieth century, during the auto-air epoch.

The urban geographer John R. Borchert’s model focuses on the development of cities in relation to the development of transportation and communication. According to Borchert’s model a city’s urban layout owes a great deal to what forms of transportation and communication were available when the city was settled.

Borchert’s model of the development of cities tracks the growth of American cities with regard to the prevailing transportation and communication technology of the time period. The auto-air epoch runs from the early twentieth century until the 1970s, it is preceded by the steel rail epoch, which lasted from the 1860s until the early 1900s.

New York City and Boston are two of the earliest American cities. They are both organized around pedestrian traffic, with narrow streets and tall-looming skyscrapers. These are features of cities that emerged during the sail-wagon epoch and the iron-horse epoch.

The sail-wagon epoch is the earliest epoch in Borchert’s model of the development of cities. Seeing as Borchert’s model focuses on the growth of American cities, the sail-wagon epoch begins in 1790 and ends in the early 1830s. It is followed by the iron-horse epoch which lasts until the late 1860s. The iron-horse epoch is followed by the steel rail epoch, which is in turn followed by the auto-air epoch, and finally by the satellite-jet epoch.

Borchert’s model of the development of cities tracks the growth of American cities with relation to the prevailing transportation and communication technology of different eras. The history of American cities is divided into five epochs, the five answer choices listed above. Chicago and St. Louis are two American cities that emerged in the second half of the nineteenth century as railroad hubs. Both these cities developed around the railroad and are classic examples of cities that evolved during the “steel-rail epoch.”

There are five epochs in Borchert’s model of the development of cities. The earliest is the sail-wagon epoch and the latest is the satellite-and-jet propulsion epoch. The second is the Iron Horse Epoch, and the third and fourth respectively are the Steel-Rail and the Auto-Air Amenity Epochs.

The Auto-Air-Amenity epoch runs roughly from 1920-1970. Within this epoch, the internal combustion engine transformed transportation.

Edge cities are secondary commerical centers of urban areas. Cities that have been abandoned are colloquially known as "ghost towns." The other types of cities do not have specific names, and are not considered edge cities.

In 2015, Tokyo is the world's largest metropolitan area, with a population of about 38 million people. None of the other options have more than 30 million people.