Task: Question Understanding
Input (English): Question: Which of the following statements best explains how the decomposition of plant and animal matter helps to form rich soils? (A) Decomposition adds silt to soil. (B) Decomposition adds water to soil. (C) Decomposition adds oxygen to soil. (D) Decomposition adds nutrients to soil.?
Output (English): explains, decomposition, plant, animal, matter, rich, soils?