Earth’s climate has an inherent variability that makes it difficult to determine the human impact on it.
Which choice below best paraphrases the sentence?
Earth’s climate has an inherent variability that makes it difficult to determine the human impact on it.
The climate of Earth is inherently variable, so it’s hard to determine the impact of humans.
Because Earth’s climate changes naturally, it is hard to know how human activity affects it.
People’s activities greatly affect Earth’s climate.
The best paraphrase of the sentence is:
“Because Earth’s climate changes naturally, it is hard to know how human activity affects it.”
Explanation: This option captures the original meaning by emphasizing the natural variability of Earth’s climate and the challenge of assessing human impact, while also maintaining clarity. The first choice is similar but does not highlight the natural changes as clearly. The third choice incorrectly suggests that human activities greatly affect the climate, which is not the main point of the original sentence.