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").
Q: Fact1: Animals use saturated fatty acids to store energy., Fact2: Animals store excess energy as fat., Question: Saturated fatty acids are used for: (A) exercise (B) Reproducing (C) solid, liquid, gas (D) energy storage (E) keeping the dog warm (F) oxidation reaction (G) an organism's body (H) Plants growth
A:
D