Answer:
A. Danube river is the answer.
The correct answer is - from solar nebula.
The Earth and the other planets in the Solar System are thought to have formed from solar nebula. This solar nebula is believed to have been a left over from the Sun's formation, being consisted of gas and dust in a disc-shape. The material in this disc-shaped gas and dust started to merge gradually, thus little by little forming bigger and bigger objects, and as the objects were getting bigger they had bigger gravitational pull so more and more material was attracted toward them. Because of the very big gravitational pull of the Sun these objects were not able to wander into the space but were instead kept close to the Sun. Because of the orbiting around the Sun, they all started to take a rounded shape. Some planets as the Earth, Venus, Mars, and Mercury became terrestrial planets, while the likes of Jupiter, Saturn, Uranus, and Neptune became gas giants.
It peaked in the late 18th Century, <span> when the largest number of slaves were captured on raiding expeditions into the interior of West Africa.
In short, Your Answer would be: Option D
Hope this helps!</span>
An alluvial fan is a triangle-shaped deposit of gravel, sand, and even smaller pieces of sediment, such as silt. This sediment is called alluvium. Alluvial fans are usually created as flowing water interacts with mountains, hills, or the steep walls of canyons.
Also, Marine sediment, any deposit of insoluble material, primarily rock and soil particles, transported from land areas to the ocean by wind, ice, and rivers, as well as the remains of marine organisms, products of submarine volcanism, chemical precipitates from seawater, and materials from outer space.
Between 1931 and 1940 a ton of soil blew out of the central and southern great. It was a period of severe dust storms that greatly damaged the ecology and agriculture during the 1930s.
