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 delta is formed by deposition of sediment at the mouth of a river by water fanning out, Fact2: Rivers provide a water supply., Question: What is formed by deposition of sediment at the mouth of a water supply fanning out? (A) a hurricane (B) soils (C) a delta (D) an ocean (E) soft soil (F) an island (G) detritus (H) spring
[EX A]: C

[EX Q]: Fact1: volcanic ash in the atmosphere decreases the temperature by blocking the sun, Fact2: Supersaturation is inferred to be a common state for atmospheric haze particles., Question: What decreases the temperature by blocking the Sun? (A) cilia (B) the Sun (C) the wind (D) haze (E) ice (F) fat (G) rain (H) acids
[EX A]: D

[EX Q]: Fact1: Most people can survive only a few days without water., Fact2: Earth is the only water planet., Question: What can most people survive only a few days away from? (A) earth (B) wetland (C) friends (D) mines (E) buildings (F) death (G) family (H) Cancer.
[EX A]:
A