It describes an experiment that addressed an unresolved question about the extent to which lunar regolith resembles terrestrial soils.

It compares two distinct methods of assessing indicators of stress in plants grown in a simulated lunar environment.

It presents evidence in support of the hypothesis that seed germination in lunar habitats is an unattainable goal.

It discusses the findings of a study that evaluated the effects of exposing a plant species to lunar soil conditions.

English

PASSAGE:
Space scientists Anna-Lisa Paul, Stephen M. Elardo, and Robert Ferl planted seeds of <em>Arabidopsis thaliana</em> in samples of lunar regolith—the surface material of the Moon—and, serving as a control group, in terrestrial soil. They found that while all the seeds germinated, the roots of the regolith-grown plants were stunted compared with those in the control group. Moreover, unlike the plants in the control group, the regolith-grown plants exhibited red pigmentation, reduced leaf size, and inhibited growth rates—indicators of stress that were corroborated by postharvest molecular analysis.

QUESTION: Which choice best states the main purpose of the text?