Which choice best describes the overall structure of the text?
A
It discusses a method used by some researchers, then states why an alternative method is superior to it.
B
It describes how researchers made a scientific discovery, then explains the importance of that discovery.
C
It outlines the steps taken in a scientific study, then presents a hypothesis based on that study.
D
It examines how a group of scientists reached a conclusion, then shows how other scientists have challenged that conclusion.
Explanation
Correct answer: B.
Choice B is the best answer. The text begins by describing how the researchers used the JWST to detect CO₂ in WASP-39b’s atmosphere. Then the text discusses the significance of this finding, both as the first evidence of CO₂ in an exoplanet’s atmosphere and as an illustration of the JWST’s potential for making new discoveries in general.
Why the other choices are wrong
Choice A
Choice A is incorrect. The text doesn’t compare two different methods, but rather focuses on one study that used the JWST.
Choice C
Choice C is incorrect. The text doesn’t present a hypothesis, but rather reports on the findings of a study.
Choice D
Choice D is incorrect. The text doesn’t mention any scientists challenging the conclusion reached by López-Morales and colleagues.