Detailed 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").
Q: Fact1: weathering means breaking down rocks from larger whole into smaller pieces by weather, Fact2: Water is a mechanical weathering force., Question: What breaks rocks down? (A) In the winter (B) Calcium carbonate (C) an engine (D) the Great Barrier Reef (E) mechanical force (F) permineralization (G) at or near the margins (H) mechanical
A:
E