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: a prism is used for refracting light, Fact2: Refraction is the bending of light cause by a speed change when it passes through different media., Question: What aspect of light changes when it passes from air into a prism? (A) power (B) seasons (C) speed (D) energy (E) a wave (F) Joules (G) heat (H) unique
[EX A]: C

[EX Q]: Fact1: energy is used for heating a building by a heating system, Fact2: Faculty offices are also in the building., Question: What contains energy to raise the temperture of an office? (A) chemical messengers (B) peachleaf willow (C) deoxyribonucleic acid (D) cooling system (E) swimming pool (F) heating system (G) gym (H) organic molecules
[EX A]: F

[EX Q]: Fact1: heavy rains cause flooding, Fact2: Flood waters rise rapidly., Question: heavy rains cause waters to what? (A) rise rapidly (B) Condensation (C) parch the land (D) dry the soil (E) Sediment (F) threatened (G) dry up (H) swamp vegetation
[EX A]:
A