Q: 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, all life relies on a relatively narrow range of what?

Options: (A). voltage; (B). Energy; (C). sun's heat; (D). low pHs; (E). Decibels; (F). spectrum; (G). Light; (H). sunlight;
The answer is:
(D).