Answer the following question: Fact 1: All life relies on a relatively narrow range of pH, or acidity. Fact 2: Biochemical reactions are catalyzed by enzymes that have very narrow ranges of optimum pH values. Given the two facts above, all what relies on a narrow range where biochemical reactions can be catalyze by enzymes?

OPTIONS: 1. sugar. 2. weathering. 3. Crops. 4. CO 2. 5. climate. 6. heat. 7. life. 8. weather.
Answer:
7.