You are presented with the question "What has a positive impact on root growth in dirt?" and the following answer choices: 
- nutrients
 - burrs
 - exercise
 - support
 - evaporation
 - looseness
 - Sand dollars
 - sun's heat

Now knowing that the looseness of soil has a positive impact on a plant 's roots' growth in that soil and soil or dirt is typically high in silica and alumina, choose the best answer.


 

      looseness   