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: 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: All chemical reactions require activation energy to get started., Fact2: Fire is a chemical reaction., Question: What does fire require to get started? (A) an engine (B) activation energy (C) water (D) energy usage (E) direct energy (F) dogs (G) activated almonds (H) adding heat
[EX A]: B

[EX Q]: Fact1: a balance is used for measuring mass of an object, Fact2: Masses are measured by difference on a balance., Question: How is mass indicated? (A) movement (B) motion (C) layers of fat (D) forces (E) set number (F) energy (G) a balance (H) similar
[EX A]:
G