Concept:Soil taxonomy groups soils by unique characteristics formed under specific climates and parent materials.
Explanation:Step 1: Oxisols are ancient, deeply weathered soils found in humid tropical regions.
Step 2: They have a highly oxidized subsurface horizon with extensive leaching.
Step 3: Therefore, Oxisols match with characteristic 3: “Very old and highly weathered.”
Step 4: Vertisols are clay-rich soils that shrink and swell, forming deep cracks.
Step 5: They are highly basic in nature, ideal for crops like cotton.
Step 6: Thus, Vertisols match with characteristic 4: “Rich in clay content and highly basic.”
Step 7: Histosols contain a very high organic matter content (20%–30%) and are at least 40 cm thick.
Step 8: Hence, Histosols match with characteristic 1: “Very rich in organic matter.”
Step 9: Entisols are young soils with no distinct horizon development beyond a thin A horizon.
Step 10: They remain unaltered from their parent rock.
Step 11: So, Entisols match with characteristic 2: “Soil lacking horizons.”
Answer:Option B: A - 3, B - 4, C - 1, D - 2