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: satellites are used to take images from space, Fact2: Images of Earth taken from space., Question: Images of Earth are taken by (A) satellites (B) light (C) Communication (D) millions (E) radar (F) Plate tectonics (G) moving plates (H) lamphreys
[EX A]: A

[EX Q]: Fact1: acid rain has a negative impact on water quality, Fact2: Sulfur dioxide causes acid rain., Question: What has a negative impact on water quality? (A) Reverse osmosis (B) fossil fuels (C) Fresh water (D) Carbon filter (E) chlorofluorocarbons (F) Sulfur dioxide (G) Pollution (H) harmful substances
[EX A]: F

[EX Q]: Fact1: sound can be used for communication by animals, Fact2: Orangutans have a vocal repertoire of about 13 sounds., Question: Orangutans can communicate by doing what? (A) mental telepathy (B) Infomercials (C) contracting (D) singing opera (E) focusing a lens (F) vocalizing (G) adding heat (H) unidirectional
[EX A]:
F