The correct answer is option 'A', which refers to deflation.

Deflation is a geological process in which loose materials, such as soil and sand, are lifted and blown away by the wind. It is an important component of wind erosion and can have significant impacts on the landscape. Here is a detailed explanation of this process:

Definition of Deflation:
Deflation is the process of wind removing loose materials, such as sand, silt, and clay, from the ground surface. These materials are transported by the wind and can cause erosion in the affected area.

Factors contributing to Deflation:
Several factors contribute to the occurrence of deflation:
1. Wind velocity: Higher wind speeds increase the likelihood of deflation as they have more energy to lift and transport loose materials.
2. Particle size and weight: Smaller and lighter particles are more easily lifted and transported by the wind.
3. Surface cover: The presence of vegetation or other surface cover can reduce the impact of deflation by providing stability and preventing loose materials from being lifted.

Process of Deflation:
Deflation occurs in several stages:
1. Suspension: As the wind blows over the ground, it picks up small particles and carries them in the air. These particles can remain suspended for long distances.
2. Saltation: Larger particles, such as sand grains, are too heavy to remain suspended in the air for long periods. Instead, they move in a bouncing motion along the ground surface. This process is known as saltation.
3. Surface creep: The constant movement of particles in suspension and saltation causes them to collide with the ground surface. Over time, this can result in the wearing down of the surface and the displacement of loose materials.

Effects of Deflation:
Deflation can have various effects on the landscape:
1. Creation of blowouts: Blowouts are depressions or hollows formed when wind removes loose materials from the ground. These features can vary in size and shape and are commonly found in desert regions.
2. Loss of topsoil: Deflation can remove the nutrient-rich top layer of soil, which is essential for plant growth. This can lead to soil degradation and reduced agricultural productivity.
3. Formation of sand dunes: When wind transports and deposits sand particles in a particular area, it can create sand dunes. These dunes can vary in size and shape and are often found in desert environments.

Overall, deflation is an important process in wind erosion, as it contributes to the transport and redistribution of loose materials by the wind. Understanding this process is crucial for managing and mitigating the impacts of wind erosion on the environment.