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: matter vibrating can cause sound, Fact2: All matter emits vibrations., Question: What kind of matter can produce sound? (A) sensory neurons (B) all matter (C) an object (D) only liquids (E) mechanical (F) only plasma (G) only solids (H) waves
[A]: B


[Q]: Fact1: Feathers help birds fly and provide insulation., Fact2: Some birds are flightless birds., Question: Why do the flightless have feathers? (A) layers of fat (B) Sublimation (C) it needs them (D) warm-blooded (E) Air conditioning (F) Radiation (G) Insulation (H) protect them
[A]: G


[Q]: Fact1: Gene flow occurs when individuals move into or out of a population., Fact2: Internal migration describes moves within a country., Question: Migration increases what? (A) root growth (B) speed (C) distance (D) voltage (E) energy usage (F) Plants growth (G) gene flow (H) layers of fat
[A]:
G