Fact 1: Heterotrophs are living things that cannot make their own food. Fact 2: Proteins are an essential nutrient for heterotrophs . Given the two facts above, what do things that cannot make their own food need as a nutrient?

Available options: (A). Energy; (B). metal; (C). animals; (D). mud; (E). Energy.; (F). protein; (G). prototype; (H). fungi;
Answer:
(F).