This, though a broad statement, is true as far as I can tell.
sand dunes form from wind
Soil is made up of air, water, minerals and organic material and is one of the most important natural resources on earth. Most life on earth depends on soil as a direct or indirect source of food. Plants and animals source their nutrients from the soil and it is home to many different forms of life.
The best answer is D because construction would be bad for the environment and take up space on the soil that is trying to be preserved. Also, for C, planting only one crop type in soil is not very beneficial to the soil at all. IT is best to plant multiple crops in the soil and move the crops to different parts of the soil each year when planting them.