91Ó°ÊÓ

The outer loose layer on the earth’s surface is known as soil. Soil is very much important for land plants. Soil formation is a slow process and it takes many years to form from rocks, organic substances, and minerals.

The soil contains inorganic materials that are in the form of rocks. Weathering and breaking of rocks form smaller particles that vary in size. Soil particles are called sand if the diameter ranges from 0.1 to 2 mm. Soil particles that are between 0.002 and 0.1mm in diameter are called silt. Even smaller particles are called clay and the diameter is less than 0.002 mm. Loams are the mixture of all soil particles having no particular size.

Therefore, the correct answer is the option ‘a’.

Sandy soils have a diameter ranging from 0.1mm to 2mm.