They weather rocks with acid. They strip the rocks of minerals. They break rocks into small pieces. They increase the density of the rocks.
I gave my students this multiple choice question: Before rock can become soil, it must undergo certain processes. One process in the formation of soil involves plants. How can plants chemically change rocks into soil?

Only one answer is correct among these 4 choices:
- They weather rocks with acid.
- They strip the rocks of minerals.
- They break rocks into small pieces.
- They increase the density of the rocks.

Could you tell me which one is correct?

They weather rocks with acid.