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: Skin color is another polygenic trait., Fact2: Most dental variations are polygenic, that is controlled by several genes., Question: Skin color is a trait controlled by what? (A) prokaryotic cells (B) one gene (C) enzymes (D) keratin (E) one's descendants (F) several genes (G) the environment (H) a single gene
[EX A]: F

[EX Q]: Fact1: wind and rain cause erosion, Fact2: Water, in the form of rain, is the most effective agent of erosion., Question: What causes erosion the most? (A) streams (B) motion (C) LEDs (D) water (E) Roads (F) rivers (G) Winter (H) wind
[EX A]: D

[EX Q]: Fact1: drought is when amount of precipitation decreases, Fact2: During drought, water supply reduced., Question: Reduced water supply occurs when what amounts decrease? (A) precipitation (B) visibility (C) fog (D) sound (E) In the winter (F) Dehydration (G) deforestation (H) salinity
[EX A]:
A