Fact 1: Air pollution can cause the pH of soil to decrease.

Fact 2: Incineration releases pollutants into the air.

Given the two facts above, answer the question "What can cause the pH of the soil to increase?" with the following options: 
- incineration
 - dry conditions
 - Greenhouse gases
 - clean water
 - contamination
 - air
 - erosion
 - clean rain


 

 incineration        