Answer: (Detailed Solution Below)
Option A: Tropical rain forest regions
Detailed Solution:
The correct answer is “Tropical rain forest regions”.
Soil leaching is particularly prominent in regions with high rainfall and intense weathering. It involves the removal of soluble substances from the soil by water moving through it, often leading to nutrient depletion.
Tropical rain forest regions are most commonly associated with soil leaching due to their high levels of rainfall. The continuous and heavy rainfall in these regions causes significant leaching of nutrients from the soil.