Textural Classification of Soils
Textural classification is a method used to categorize soils based on their particle size distribution. It is an important aspect of soil classification as it provides valuable information about the engineering properties and behavior of soils. The classification is based on the percentages of sand, silt, and clay present in the soil.

Coarse-Grained Soils
Coarse-grained soils primarily consist of sand and gravel particles. They have relatively larger particle sizes compared to fine-grained soils. The textural classification system divides coarse-grained soils into several categories based on the percentage of fines (silt and clay) present. Some common categories include:

1. Well-graded gravel (GW): This category represents soils with a broad range of particle sizes and a relatively uniform distribution. They have good drainage characteristics and high shear strength.

2. Poorly graded gravel (GP): Soils in this category have a narrow range of particle sizes with little or no fines. They exhibit poor drainage and low shear strength.

3. Silty gravel (GM): These soils contain a significant amount of silt in addition to gravel particles. They may have reduced drainage and reduced shear strength compared to well-graded gravel.

4. Clayey gravel (GC): Soils in this category contain a significant amount of clay in addition to gravel particles. They may have poor drainage and low shear strength.

In the context of the given options, coarse-grained soils (option C) are most suitable for textural classification. This is because the textural classification system is primarily designed to categorize soils based on their particle size distribution, and coarse-grained soils have larger particle sizes compared to fine-grained soils. Clay soil (option A) and wet soil (option B) are fine-grained soils, while soil with moisture (option D) does not provide enough information about the particle size distribution to determine its textural classification. Therefore, option C is the most suitable choice for textural classification.