Fact 1: High temperatures can cause an object to combust.

Fact 2: Combustion of fuel is one of the main causes of air pollution.

Given the two facts above, answer the question "What can high temperatures cause?" with the following options: 
- hyperthyroidism
 - Dehydration
 - Greenhouse gases
 - chemical reaction
 - global warming
 - contamination
 - Air pollution
 - sweating


 

       Air pollution  