Final answer:
If the Sun doubled in temperature, the habitable zone, which is essential for life due to the presence of liquid water, would move farther away from the Sun to reflect the increased luminosity and energy output.
Step-by-step explanation:
If the Sun were to suddenly double in temperature, the habitable zone would move farther from the Sun. The habitable zone is the region around a star where conditions may allow for liquid water to exist, a critical requirement for life as we know it. As a star like the Sun gets hotter and more luminous, this zone extends outward because the increased energy output would heat up the planets and potentially trigger a runaway greenhouse effect on those closer to the star, rendering them too hot to be habitable.
Historically, Venus was once within the habitable zone, but over time as the Sun's output increased, Earth became the prime candidate for hosting life. Furthermore, it's important to recognize that even if a planet such as Venus were moved to an orbit within the habitable zone, the lack of water means it still may not support life. Therefore, the correct answer is (c) The habitable zone would move farther from the Sun.