Fact 1: Changes in the pH of soil can cause plants to die.

Fact 2: Sulfur lowers pH in soil.

Given the two facts above, answer the question "What can cause plants to die?" with the following options: 
- Planting flowers
 - Winter
 - Pollution
 - Condensation
 - Photosynthesis
 - Sulfur
 - coal
 - bacteria


 

      Sulfur   