The correct answer is - a. deposition.
The deltas are formed at the mouths of the rivers right before they enter a large water body, like ocean, sea, or lake. The rivers carry lot of material with them, and they do not have any problem carrying it while they are moving faster, but when they are slowing down significantly, they lose the force required to carry the material, so the material starts to deposit on the river banks. As the material deposits, it makes it hard for all of the river's water to pass through its river bed that is becoming partially blocked, so the river starts to branch out, and seen from above it takes a triangular shape if the peripheries are outlined, or as a tree that is branching out.

The Correct choice is C
<u>Demography</u> is the study of human populations and how they grow or decline.
It should be the third answer choice. The nations of OPEC chose to cooperate primarily in order to manage the supply of a natural resource.
OPEC works to balance both the production and price of oil so that customers are able to receive a consistent supply of petroleum and investors in the industry are able to make profit from their investments.
Geographers use map projections to translate the planet in a two dimensional representation. Unfortunately, you can’t display 3D surfaces perfectly in two dimensions, distortions always occur. There are many different projections that are commonly used throughout the world.