Fact 1: Moss causes chemical weathering.

Fact 2: Chemical weathering causes chemical changes in the minerals of a rock.

Given the two facts above, answer the question "What causes chemical changes in the minerals of a rock?" with the following options: 
- moss
 - hitting it with a hammer
 - steady temperature
 - bad music
 - copper
 - iron
 - sodium
 - coal


 

 moss        