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: an organism requires energy for growth, Fact2: Different organisms have different growth requirements and growth rates., Question: What is a requirement whose amount varies between organisms? (A) food (B) energy (C) existence (D) entropy (E) sunlight (F) H20 (G) entity (H) Energy.
B