Answer:
The noun phrase that completes the sentence is A. , a relatively rare event,: <em>A total solar eclipse, a relatively rare event, causes a change in the amount of visible light.</em>
Explanation:
A <u>noun phrase</u> is a group of words in a sentence that act together as a noun. In this way, the <u>noun phrase</u> can act as object, subject, prepositional object or apposition, like in this case. Therefore, option A is the correct answer.
I believe it's detail, but double check in-case I'm wrong.
