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: Mammals generate heat mainly by keeping their metabolic rate high., Fact2: Faster metabolism means more calories consumed, and usually, weight loss., Question: How do mammals generate heat? (A) freezing (B) Ice cubes (C) layers of fat (D) Taking pictures (E) with their fur (F) energy of moving objects (G) Consuming calories (H) Movement of an air mass
G