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: a light bulb is used for seeing in the dark, Fact2: Light is emitted by a light bulb., Question: What is required for seeing? (A) dark (B) sun (C) light (D) wind (E) retina (F) eyes (G) photons (H) copper
[A]: C


[Q]: Fact1: Some viruses can cause cancer., Fact2: Cancer is an example of a mutation in cells., Question: What can mutate cells? (A) Allergies (B) water (C) fruits (D) flow of electrons (E) vegetables (F) harmful substances (G) rays or beams (H) some viruses
[A]: H


[Q]: Fact1: a greenhouse is used to protect plants from the cold, Fact2: Plants are grown in greenhouses and protected from wild butterflies., Question: Plants are grown where they are protected from what? (A) the sky (B) disease (C) storms (D) cold air (E) the water (F) the warmth (G) sun's heat (H) the cold
[A]:
H