The correct answer is - grow wheat or oats.
The Great Plains region is a semi arid region. That means that it has relatively low amount of precipitation. Also, the precipitation occurs only in certain parts of the year, and there's relatively long droughts in between. This has led to the Great Plains region to naturally be a grassland. The grasses have contributed with their quick decomposition for a very fertile soil with deep top humus layer. In order to use the soil, the climate conditions, as well as to retain the soil's high productivity, the farmers have mainly orientated towards the farming of crops like the wheat and the oats. They do not require a lot of water, have characteristics that make them suitable for the climate, and their roots and leftovers from the steams are decomposing very quickly which retains the soil's fertility.
Social, cultural and economic factors influence fertility, mortality and migration rates. Migration is affected by various factors like age, sex, marital status, education, occupation, employment etc. Age and sex are main demographic factors that affect the migration.
The answer is - adiabatic lapse rate.
Adiabatic lapse rate refers to the rate at which the air expansion cools. For the dry air it has the value of 9.8 degrees per kilometer. When the air that is saturated starts rising and cools, the process of condensation of water vapor begins, releasing latent heat in the process.
Answer:
D. Above the Arctic Circle