Final answer:
Soil is the basic component of d. soil. It consists of inorganic mineral matter and organic matter, along with water and air. The presence of humus in soil improves its structure and provides water and minerals to plants.
Step-by-step explanation:
Soil is the basic component of d. soil. It consists of four major components: inorganic mineral matter, organic matter, water and air, and living matter. The inorganic material of soil consists of rock broken down into smaller particles, while the organic material is made up of decomposing plant and animal matter, as well as microorganisms involved in decomposition. The organic material, known as humus, improves soil structure and provides plants with water and minerals.