Fact 1: The looseness of soil increases the amount of oxygen in that soil.

Fact 2: Soil oxygen effects on root development.

Given the two facts above, answer the question "Why does it help for dirt to be loose?" with the following options: 
- Physical weathering
 - adding heat
 - It used to be covered by water
 - permineralization
 - water conservation
 - Roots get more oxygen
 - The area was once underwater
 - Riding a bike


 

      Roots get more oxygen   