Fact 1: All life relies on a relatively narrow range of pH, or acidity.

Fact 2: Acids have low pH's.

Given the two facts above, answer the question "All life relies on a relatively narrow range of what?" with the following options: 
- voltage
 - Energy
 - sun's heat
 - low pHs
 - Decibels
 - spectrum
 - Light
 - sunlight


 

    low pHs     