Instructions: 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").
Input: Fact1: when a metal rusts , that metal becomes orange on the surface, Fact2: Metal turns to rust via oxidation., Question: what makes metal orange? (A) pigmentation (B) heating (C) tubular organ (D) antigens (E) chondrocytes (F) radiation (G) oxidation (H) several genes
Output:
G