Final answer:
The most clear and concise way to rewrite the provided sentence is option d, which explains our extensive knowledge about the sun being attributable to its proximity to Earth.
Step-by-step explanation:
The best way to rewrite the wordy sentence to make it more clear and concise without changing its meaning is option d: "We know more about the sun than any other stars because it is closest to Earth." This option combines all the relevant information into one concise statement. It validates why we have the most knowledge about the sun - because of its proximity to Earth - thus, conveying the essence of the original sentence efficiently.
The sun, being our local star and the nearest star to Earth, stands out from other stars, which are enormous balls of glowing gas generating energy through nuclear reactions. Unlike other distant stars, such as Proxima Centauri, the sun is much closer, making it appear brighter and allowing us to study it in more detail.
Moreover, the vast distances between Earth and other stars mean that even the brightest-looking stars are not necessarily the closest to us. Instead, their brightness is due to their high energy output, and many of these stars are spectral type B, vastly different from our sun and visible without telescopes despite their great distances from Earth.