I think the answer is obviously letter D
State: California
City: New York City
XD XD XD XD XD XD XD XD XD XD XD XD
The Saudi Arabia politics are take place in the context of a totalitarian absolute monarchy with some Islamic (Wahhabi Islam) lines, and the King is both the Saudi Arabia's head of state and absolute monarch (i.e. he is the head of government). The King also serves as the head of the Saudi royal family, the House of Saud, which is also why the country bears the name that it has.
The correct answer is - biomass from the decomposing grasses.
The Midwest is a region known for its highly fertile soil. The reason for this is that the weathered bedrock combines with huge amounts of biomass. The biomass is almost entirely form the grasses. The grasses grow naturally in this region and they dominate the landscape. They grow and die out relatively quickly, as most of those grasses are one season grasses. They manage to create very large amounts of biomass every year, and also they decompose very quickly. The grasses also are high in nutrients, so once decomposed, they give the soil a lot of nutrients as well, which makes it very fertile and suitable for agriculture.