The correct answer is A. Global warming is caused by the fuels people.
Step-by-step explanation
According to the paragraph, it can be inferred that its main idea is "A. Global warming is caused by the fuels people" cause the author first expresses the problem of global warming by saying that "Global warming is the heating up of Earth's climate. It is also called climate change "and later states the cause of this problem by saying that" Scientists think that it comes from the fuel that people use. People burn these fuels to make energy. Many things from cars to lights run on this energy ". Therefore, it can be said that the correct answer is A.