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").

[EX Q]: Fact1: mechanical weathering is when rocks are broken down by mechanical means, Fact2: Water is a mechanical weathering force., Question: What  weathers rocks? (A) soil (B) streams (C) a delta (D) calcite (E) erosion (F) water (G) grass (H) the sun
[EX A]: F

[EX Q]: Fact1: Air pollution harms the respiratory and circulatory systems., Fact2: Cars are a significant source of air pollution., Question: What harms the respiratory and circulatory systems? (A) oil (B) rain (C) sulfur (D) cars (E) tires (F) coal (G) tar (H) bicycles
[EX A]: D

[EX Q]: Fact1: rain causes erosion, Fact2: Rain is liquid precipitation., Question: what causes erosion? (A) standing water (B) coastlines (C) mouth of rivers (D) ice wedging (E) liquid precipitation (F) Physical weathering (G) trees (H) gravity
[EX A]:
E