You are presented with the question "All life relies on a relatively narrow range of what?" and the following answer choices: 
- voltage
 - Energy
 - sun's heat
 - low pHs
 - Decibels
 - spectrum
 - Light
 - sunlight

Now knowing that all life relies on a relatively narrow range of pH, or acidity and acids have low pH's, choose the best answer.


 

    low pHs     