instruction:
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").
question:
Fact1: knowledge of the stars can be used to navigate, Fact2: Of course, astronomers also study stars., Question: What can be used to navigate? (A) music (B) backbones (C) astrology (D) cilia (E) magic (F) sponges (G) astronomy (H) lamphreys
answer:
G

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: producing thrust causes something to move, Fact2: Then the engine spins up and starts producing thrust., Question: What do engines cause? (A) silence (B) Something to move (C) reproduction (D) birth (E) energy of moving objects (F) heat energy (G) Chemical energy (H) harmful substances
answer:
B