You are presented with the question "What cause pollution to disperse?" and the following answer choices: 
- low pressure systems
 - fissures of hot, acidic water
 - zero pressure systems
 - fossil fuels
 - harmful substances
 - no pressure systems
 - high pressure systems
 - Greenhouse gases

Now knowing that high pressure systems cause clear weather and during windy weather, the pollution is dispersed and cleared away, choose the best answer.


 

       high pressure systems  