Comprehension:
Read the following passage carefully and answer the questions that follow
There can be no greater example of a mankind’s creative genius than for him to create new abodes of life throughout the solar system. Today, with an increasing population of more than six billion people and the fear of possible disaster, the need for an alternate home for mankind has become urgent. Mars is the only planet in our solar system, besides Earth – that has all the ingredients necessary to support life. Though the average surface temperature on Mars is frigid and it is a desolate lifeless planet, Mars once had an atmosphere thick and warm enough to allow for the flow of liquid on its surface.
If it is ever done, transforming a dry, desert-like Mars into a lush environment that can support the flora and fauna of the Earth, will be a mammoth task requiring decades or maybe centuries! Two methods have been proposed to make this a reality. One is placing large orbital mirrors that will reflect sunlight and heat onto the polar caps of Mars, which would melt the ice there. Gradually, the rise in temperature would release the greenhouse gases and heat the planet.
Another option would be to set-up solar-powered, greenhouse gas producing factories. Imitating the process of photosynthesis, the atmosphere of Mars would be oxygenated to the extent that people would survive on Mars with only a breathing apparatus.
While we may reach Mars this century, it would take several millennia for transforming it into a planet wherein plants and animals can flourish.
Choose the most appropriate option to complete the following:
The purpose of using orbital mirrors on Mars would be to -
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → modify its temperature and release greenhouse gases to sustain life.
The mirrors would reflect sunlight and heat onto the polar caps and melt the ice; "gradually, the rise in temperature would release the greenhouse gases and heat the planet". The aim is to warm Mars and release greenhouse gases so that it can support life.
Why the Other Options are Incorrect?
Option 1: brighten up the planet by reflecting sunlight on it. — Incorrect. Wrong focus: reflecting sunlight is how the mirrors work; the purpose is heat, not light.
Option 3: melt the polar ice caps to generate water. — Incorrect. Too narrow: melting the ice is only a step; the passage says it leads to the release of greenhouse gases that heat the planet, and does not speak of making water.
Option 4: decrease the temperature and maintain the cold atmosphere of the planet. — Incorrect. Contradicted: this is the reverse of the plan, which is to raise the temperature.