The correct answer is: I and IV
Imagine a very large town in the center of a uniformly fertile plain; an isotropic space. Beyond the fertile space extends a desert that isolates the town from the rest of the world. There are no other populations. The only market buys all the agricultural production of the region, and is transported by the shortest route (a straight line).
In these conditions all men behave similarly in economic matters, that is, they have the same needs and abilities, produce equally and have a total knowledge of space and rationally conducts to achieve maximum performance, is the economic man. The differences in the cost of transport are taken into account depending on the distance, the quantity and the perishability of the merchandise.
Obviously, in the real world there are no given isotropic space conditions, there are differences in the fertility of the land, differences in topography and access to markets due to communication routes (faster or cheaper), and there is usually more than one market in the region. All this would cause the concentric model to adopt an irregular aspect, although basically valid. Let us think that Von Thünen's model belongs to the beginning of the 19th century, when national markets and modern means of transport, such as railways, were not yet created.
