Explanation:

- Alluvial Soil:

- Consists of sand, silt, and clay in varying proportions.

- Found in river basins and is fertile with potash and phosphoric acid.

- Can be classified based on age (Khaddar and Bhangar).

- This is the correct answer. *“”*

- Laterite Soil:

- Rich in iron and aluminum.

- Not known for containing potash or phosphoric acid.

- Found in regions with high rainfall.

- Arid Soil:

- Typically sandy, poor in organic matter.

- Contains soluble salts.

- Found in dry regions.

- Black Soil:

- High clay content and known for retaining moisture.

- Rich in calcium carbonate, magnesium, potash.

- Often referred to as Regur soil.

Alluvial Soil meets all the characteristics described, making it the correct choice.