You are presented with the question "What has a positive impact on a plant's roots' growth?" and the following answer choices: 
- reducing acid rain
 - color of dirt
 - looseness of dirt or compost
 - basic building blocks of life
 - biological diversity
 - lead in the soil
 - Evaporation of water
 - a lack of soil

Now knowing that the looseness of soil has a positive impact on a plant 's roots' growth in that soil and to improve soil, add several top-dressings of dirt or compost, choose the best answer.


 

   looseness of dirt or compost      