You are presented with the question "Organisms rely on a relatively narrow range of what?" and the following answer choices: 
- Decibels
 - water
 - food
 - relativity
 - acidity
 - spectrum
 - balance
 - Light

Now knowing that all life relies on a relatively narrow range of pH, or acidity and all organisms have a life-span, choose the best answer.


 

     acidity    