Answer the following question: Fact 1: All life relies on a relatively narrow range of pH, or acidity. Fact 2: All organisms have life cycles. Given the two facts above, what relies on a relatively narrow range of acidity?

pick from the following.
[i] organisms
[ii] carbon
[iii] animals
[iv] hydrogen
[v] density
[vi] trees
[vii] Most plants
[viii] barnacles
Answer:
[i]