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: a glacier causes mechanical weathering, Fact2: Pysical weathering is the mechanical breakdown of rocks., Question: What do glaciers do to rocks? (A) form them (B) melt them (C) protect them (D) storing water (E) throw them (F) It expands (G) Water expanding (H) break them down
Output:
H