The relative percentage of different soil separates (sand, silt, clay) is called

Correct option is C

Soil consists of different sized particles such as sand, silt, and clay, each influencing soil behavior. The proportion in which these particles are present determines important physical properties of soil. This relative percentage remains almost constant and affects water retention, aeration, and nutrient holding capacity. Such relative proportion of soil separates is known as soil texture.
Information booster: Soil texture is a basic and permanent soil property that does not change easily with management practices. It is used to classify soils into textural classes such as sandy, loamy, and clayey soils. Soil texture strongly influences irrigation scheduling, tillage operations, and crop suitability. The soil textural triangle is a standard tool used to determine soil texture based on particle percentages.
Why other options are incorrect: (a) Soil structure refers to arrangement of particles into aggregates, not their proportion. (b) Soil aggregation describes binding of particles, not textural composition. (d) Soil profile refers to vertical arrangement of soil horizons.