You will be given a definition of a task first, then some input of the task.
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: mechanical weathering is when rocks are broken down by mechanical means, Fact2: Water is a mechanical weathering force., Question: What are broken down by water? (A) rocks (B) germs (C) shells (D) lipids (E) soils (F) sand (G) dead (H) fungi
Output:
A