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 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
[EX A]: C

[EX Q]: Fact1: Biomass is the total mass of organisms at a trophic level., Fact2: Each stage is a trophic level., Question: The total mass of organisms in an environmental stage is called what? (A) food pyramid (B) extinction (C) ecological pyramid (D) food chain (E) vegetation (F) food (G) ligt (H) biomass
[EX A]: H

[EX Q]: Fact1: when a river floods , that river deposits soil in flood plains, Fact2: Flood plains are generally marshy., Question: where is soil deposited when a river floods? (A) aqueous solution (B) near the shoreline (C) mountains (D) colder and wetter (E) the sky (F) Inches or fractions of inches. (G) deserts (H) generally marshy areas
[EX A]:
H