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").
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Question: Fact1: volcanic ash in the atmosphere decreases the temperature by blocking the sun, Fact2: Ash clouds are a particular problem for aircraft., Question: What are particular problems for aircraft in the atmosphere? (A) transportation (B) clog airways (C) extremely low humidity (D) volcanic clouds (E) feedback mechanisms (F) negative feedback (G) gas spreads in the air (H) very complex

Answer: D


Question: Fact1: cold fronts cause thunderstorms as they pass by, Fact2: If cold air replaces warm air, it is called a cold front., Question: What does cold air replacing warm air cause? (A) Greenhouse gases (B) Pollution (C) Dehydration (D) thunderstorms (E) steady barometer readings (F) hypothyroidism (G) constant air pressure (H) stagnant air temperature

Answer: D


Question: Fact1: matter vibrating can cause sound, Fact2: All guitars produce sound through the mechanical vibration of strings., Question: What do guitar strings do? (A) Charge the guitar (B) Relieve pain (C) Vibrates (D) reproduce (E) squeeze (F) Bend (G) Create silence (H) Mute the guitar

Answer:
C