Black cotton soil is rich in

✅Explanation:
-Black cotton soil, also known as Vertisol, is characterized by its high content of montmorillonite clay minerals.
-Montmorillonite has a high swelling and shrinking capacity, which causes the soil to expand when wet and crack when dry, typical characteristics of black cotton soil.

📌 Other Options Explanations:
-Option B: Kaolinite: Kaolinite is a clay mineral with a 1:1 lattice structure and low shrink-swell capacity compared to montmorillonite. It is commonly found in less fertile, well-drained soils.
-Option C: Illite: Illite is a 2:1 clay mineral with moderate shrink-swell capacity. It is often found in temperate regions and exhibits intermediate properties between montmorillonite and kaolinite.
-Option D: Chlorite: Chlorite is a 2:1:1 clay mineral with relatively low shrink-swell capacity. It is typically found in soils derived from metamorphic rocks and exhibits good water-holding capacity.