Which sentence would be the best re-statement of this paragraph from the article “Those Mysterious Comets”?

Because comets are made of water and dust, they reflect light well. This means you can see some comets very easily. But scientists only know about comets that make regular appearances. This means that most comets have not been discovered yet. Scientists rely on people who watch the skies regularly to report new comets.
Group of answer choices

A. Comets are made of water and dust.

B. Only scientists using strong telescopes can identify new comets.

C. There are no new comets to be found today.

D. Comets can be seen easily, and ordinary people can help scientists spot them.

answer fast please