You are presented with the question "What do the average number of individuals per unit of area or volume affect?" and the following answer choices: 
- that material's properties
 - our landscape
 - balance of the environment
 - death and devastation
 - important habitats
 - swamp vegetation
 - the environment
 - Animal survival

Now knowing that population density is the average number of individuals per unit of area or volume and population densities affect the balance of the environment, choose the best answer.


 

   balance of the environment      