The correct answer is - A. reduce the amount of sediment deposited on floodplains and increase the amount of sediment deposited at the river's mouth.
The Mississippi River is one of the biggest rivers in the world. It is also a river that carries with it very large amount of sediments. The levees built along side it though do not allow the natural process of deposition of sediments on the floodplains of the river. That results in the river carrying the sediments down to the river mouth. Because of this, the river mouth is becoming an ever-growing delta because of the constant deposition of very large amounts of sediments. This also causes lot of the sediments to end in the coastal parts of the sea, which makes the sea waters shallower and murkier, as well as creating new land forms alongside the coast from the deposited material.
It was the most accurate calendar of the time!
For the given situation above, I think there is a lack of information regarding the one you posted. Here is what I got about the Cordillera Region.
The word Cordillera is actually a Spanish word that means mountain ranges. The climate is warm and temperate in Cordillera. Cordillera has a significant amount of rainfall during the year. This is true even for the driest month. The average annual temperature in Cordillera is 21.2 °C. The average annual rainfall is 1431 mm.
This would probably be D since foreign people would work for less money.