Given the task definition and input, reply with output. 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: lungs are used for breathing air by land animals, Fact2: Elephants are the largest animals on land., Question: What uses lungs for breathing air? (A) rocks (B) some mammals (C) Frogs (D) monotremes (E) humans (F) bacteria (G) elephants (H) oak trees

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
G