You will be given a definition of a task first, then some input of the task.
In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Fact1: All life relies on a relatively narrow range of pH, or acidity., Fact2: Acids and bases are a part of everyday life., Question: what substances are relied on for life? (A) magma (B) plants (C) poison (D) food (E) oxygen (F) fat (G) bases (H) battery acid
Output:
G