Question

with the prospect of deep space exploration on the horizon, nasa has recently turned more of its attention toward understanding the challenges that could threaten a long - distance space expedition. in particular, nasa has begun exploring the impact of isolation on space voyagers, as their journeys will likely take them away from earth and most other humans for months or even years. studies already suggest that the greatest psychological threat to astronauts is extended isolation. nasa’s human research program has noted that feelings of isolation worsen over long periods. accordingly, the longer astronauts are away from earth, the bigger the mental health challenges they are likely to face. researchers surfaced this problem during a russian study called the mars - 500 project. the study was meant to simulate a 520 - day mission to mars with a crew of six. the effects of isolation became increasingly alarming as the study wore on: participants stopped following the instructions of mission control, grew distrustful of outsiders, lost interest in communicating, and spent more time in bed. before the dream of deep space exploration can become reality, nasa will need to ensure that its astronauts are ready to handle the vast and lonely emptiness of the cosmos. read the following incomplete summary of the text: nasa is looking at how isolation affects humans. studies suggest that isolation over long periods is extremely problematic. which sentence best completes the summary? choose 1 answer: a the isolated crew of the mars - 500 study exhibited more and more troubling behavior with the passage of time. b the isolated crew of the mars - 500 study reported improvements in mood after being shown images of earth. c the name of the program at nasa that studies the effects of isolation on astronauts is the human research program. d the mars - 500 study shows that a nasa mission to mars is currently too dangerous to consider.

Explanation:

The text focuses on the negative impacts of isolation on astronauts, with the Mars - 500 study as an example of such impacts. Option A continues the theme of isolation's problematic nature by highlighting the crew's troubling behavior over time. Option B is about mood improvement which is not in line with the overall negative - impact theme. Option C just gives the name of a program, not adding to the summary of the problem of isolation. Option D is about the danger of a Mars mission which is not the main point of the summary about isolation's effects.

Answer:

A. The isolated crew of the Mars - 500 study exhibited more and more troubling behavior with the passage of time.