The process of soil formation involves the following steps: Accumulation of materials, leaching and losses (because of weather factors particles are leached and eroded away or taken up from the soil by plants), Transformation and illluviation (the chemical weathering of silt, sand, and the formation of clay minerals as well as the change of organic materials into decay resistant organic matter), podsolisation and translocations (strong acidic solutions breakdown the clay minerals). From the given options soil formation involves both physical and chemical weathering of rocks. Correct answer:D
