The correct answer is option 1, Laterite. Leaching refers to the process of water carrying away dissolved minerals from the soil. It is most prominent in soil types that have a high level of rainfall. Laterite soil is a tropical soil type that is found in regions with heavy rainfall. It is characterized by its high iron content and its tendency to become hardened when exposed to dry conditions. Due to the heavy rainfall in these regions, the water easily percolates through the soil, carrying away the dissolved minerals and nutrients. This leaching process can result in the soil becoming infertile and lacking in essential nutrients. In contrast, soils such as red soil (option 2), regur soil (option 3), and desert soil (option 4) have different characteristics that make them less prone to leaching. Red soil is typically well-drained and has good fertility, regur soil is known for its high clay content and water holding capacity, and desert soil is often arid and lacks sufficient rainfall for leaching to occur. Therefore, the maximum leaching is observed in laterite soil.