The correct answer is : A -B
The wind is an efficient erosion agent of fine and loose materials, capable of plucking, lifting and transporting particles, however, its capacity to erode compact and hard rocks is very limited. If the surface is made of hard rock, the wind is unable to cause appreciable changes because the cohesive force of the material exceeds the force exerted by the wind. Only in those places where the exposed surface contains loose or cohesive mineral particles, the wind can manifest its full erosion and transport potential. The speed determines the ability of the wind to erode and drag particles, but also influences the character of the materials, the topography of the terrain, the protective efficiency of the vegetation, etc.
In the phenomenon of wind erosion, the surface on which the wind acts is decisive. Its alteration is not limited to points or limited areas as occurs with water erosion; the action of the wind is exerted on the entire surface. In large spaces, erosion often produces excavations of shallow depressions called basins, basins or deflation depressions. They originate in areas more or less flat and devoid of vegetation where the soil is exposed to the action of the wind. The fine particles (clays and silts) are lifted by vertical currents that exceed the decantation velocities; the dust diffuses into the atmosphere to heights ranging from a few meters to several thousand. The height depends on the intensity of the wind turbulence, its duration and the size of the particles. As a result, a dense cloud, called a dust storm, can occur.
Even though this should be a Geography question, the correct answer is A. Soil.
Wind is characterized as a large scale flow of gasses, in Earth's case, mostly air. The correct answer is soil because it has the smallest particle size of the options. Mud is incorrect because it is soggy and doughy, being hard to move with air. While a rock and a mountain both have high density and bigger size, which would be harder for the wind to move, the soil has a bunch of small sized grains which are lighter and should be easily carried by the wind in smaller portion, especially in areas where there is less plants and roots.
