16. (08.05 mc) which of the following changes in modern agriculture challenges the validity of von thünen's theory? (3 points) i. increased consumer demand for organic food ii. decreased transportation time from farm to market iii. global demand for certain crops iv. increased mechanization of agriculture has increased crop yields i and ii i and iii i and iv ii and iii ii and iv

The answer is II and IV. Von Thunen's Theory 's proncipal variable is distance. If the crop field is close to the consumption area (a city), the cost of that land will be expensive. If it is far away, the cost of the land will reduce but the transportaions ones will increase. With the improvement of transportation the distance won't be such a determinant factor, those costs reduce considerably.

With the improvement of crop yields, wich Von THunen did not had in consideration, a single crop can provide a lot of food making the cost of the land reduce its importance.

the indians crossed artificial boundaries, setting the stage for conflict

monopolies  came to the united states with the colonial administration. the large-scale public works needed to make the new world hospitable to old world immigrants required large companies to carry them out. these companies were granted exclusive contracts for these works by the colonial administrators. even after the american revolution, many of these colonial holdovers still functioned due to the contracts and land

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