The correct answer is - C. The river carried enormous amounts of silt.
The Yellow River, got this nickname because it is yellowish from the enormous amounts of silt it carries. When there were heavy rains, or the snow was melting, the river got more water, but also more silt, so the silt was partially blocking the free movement of all of the water, so it was flooding the surrounding are. In one way, the floods were terrible because they were destroying pretty much everything on their way, but on the other side, were living huge amounts of deposits that were fertilizing the soil for the agriculture.
Rural settlement means people living in rural areas, that is, not in the cities (which are urban areas).
Less and less people live in rural areas because there are less jobs there than in the city as our farming becomes more and more industrialized - before more people had to work on the farm, as more things had to be done by hand.
Alfred Kroeber did explain the theory of environmental determinism first so that means the statement is true.
X=53°
alternate exterior angles theorem
The correct answer is - industry.
The developing countries are most often occupied with making the economies heavily focused on the industry, so the countries engage into a big industrialization process.
The industries are usually based around manufacturing of the natural resources that the country has, and most often those are the metal ores, the agricultural products, creating materials...
The developing countries usually have a relatively big economic growth, and that is due to the bad economic basis that they had as a starting point.