Given the task definition and input, reply with output. 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: a glacier causes mechanical weathering, Fact2: Mechanical weathering happens when things like ice physically break rock apart., Question: What do glaciers do to rocks? (A) break off (B) Turns them into ice (C) Regrows it (D) Creates more rocks (E) Dries them out (F) protect them (G) Breaks them apart (H) cause their death
G