Which of the following are the main components of soil?

The main components of soil include minerals, organic matter, water, and air, which are essential for creating a fertile environment for plant growth.

Minerals provide essential nutrients for plants and originate from the weathering of rocks. Organic matter, derived from decomposed plant and animal material, enhances soil fertility and structure, promotes biological activity, and improves moisture retention. Water is crucial as it facilitates nutrient uptake by plants, while air in the soil allows for respiration processes among soil organisms and plant roots.

While the other options mention important aspects of soil composition, they do not encompass the full array of vital components. For instance, one option features only water, minerals, and gas, overlooking the significance of organic matter. Another focuses solely on organic matter, air, and water, excluding the critical role minerals play. Finally, one option that mentions sand, silt, and clay exclusively fails to recognize the contributions of organic matter and air, which are integral to maintaining soil health and function. Thus, the comprehensive inclusion of minerals, organic matter, water, and air correctly identifies the essential components that contribute to soil's ability to support plant life.