You are presented with the question "what does the average number of individuals per unit of area do?" and the following answer choices: 
- It decreases
 - doesn't exist
 - allow growth
 - remains static
 - competing for resources
 - vary considerably
 - population gravity
 - rapid expansion

Now knowing that population density is the average number of individuals per unit of area or volume and population density varies considerably, choose the best answer.


 

      vary considerably   