sun, water, clay, and sand. sand, clay, wind, and pebbles. sand, clay, dead plants, and dead animals. leaves, twigs, sun, and wind.
I gave my students this multiple choice question: Soil is a mixture of many substances which may include

Only one answer is correct among these 4 choices:
- sun, water, clay, and sand.
- sand, clay, wind, and pebbles.
- sand, clay, dead plants, and dead animals.
- leaves, twigs, sun, and wind.

Could you tell me which one is correct?

sand, clay, dead plants, and dead animals.