Q: 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: chemical weathering causes iron in rock to oxidize, Fact2: Oxidation of iron minerals causes the redness of the rocks., Question: chemical weathering causes redness of the rocks containing what? (A) iron (B) Urea (C) Gases (D) red stones (E) matter (F) gems (G) coal (H) oranges
A:
A