Many astronomers believe that the presence of liquid water is the single most important factor in determining a planet's habitability. However, researcher Dr. Elena Rostova argues that a planet’s magnetic field is equally critical. Without a robust magnetic field, solar winds can strip away a planet’s atmosphere, preventing liquid water from ever accumulating on the surface. Thus, Rostova’s team focuses their search on exoplanets that exhibit signs of strong magnetospheres.
Which choice best describes the function of the underlined sentence in the text as a whole?
- AIt summarizes the main finding that Rostova's team reached at the conclusion of their research.
- BIt introduces a potential flaw in the methods Rostova's team uses to locate exoplanets.
- It explains the process by which a weak magnetic field prevents a planet from maintaining liquid water.Answer
- DIt describes a rare scenario in which liquid water is not necessary for a planet to support life.
Answer
It explains the process by which a weak magnetic field prevents a planet from maintaining liquid water.
The correct option correctly identifies that the underlined sentence describes the mechanism (atmosphere stripping by solar winds) that prevents liquid water accumulation when a magnetic field is absent. This explanation supports Rostova's argument that a magnetic field is critical to habitability.
Step-by-Step Solution
Key Concept
Identifying the rhetorical function of a specific sentence within a passage, particularly how it supports a main claim.